Programs & Examples On #Navicat

Navicat is a series of graphical database management and development software produced by PremiumSoft CyberTech Ltd. for MySQL, MariaDB, Oracle, SQLite, PostgreSQL and Microsoft SQL Server.

How to send email from MySQL 5.1

If you have vps or dedicated server, You can code your own module using C programming.


 * File:   para.h
 * Author: rahul
 * Created on 10 February, 2016, 11:24 AM

#ifndef PARA_H
#define  PARA_H

#ifdef  __cplusplus
extern "C" {

#define From "<[email protected]>"
#define To "<[email protected]>" 
#define From_header "Rahul<[email protected]>"   
#define TO_header "Mini<[email protected]>"   
#define UID "smtp server account ID"
#define PWD "smtp server account PWD"
#define domain ""

#ifdef  __cplusplus

/* PARA_H */


 * File:   main.c
 * Author: rahul
 * Created on 10 February, 2016, 10:29 AM
#include <my_global.h>
#include <mysql.h>
#include <string.h>
#include <ctype.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <arpa/inet.h>
#include <unistd.h>
#include "time.h"
#include "para.h"


my_bool SendEmail_init(UDF_INIT *initid,UDF_ARGS *arg,char *message);
void SendEmail_deinit(UDF_INIT *initid __attribute__((unused)));
char* SendEmail(UDF_INIT *initid, UDF_ARGS *arg,char *result,unsigned long *length, char *is_null,char* error);

 * base64
int Base64encode_len(int len);
int Base64encode(char * coded_dst, const char *plain_src,int len_plain_src);

int Base64decode_len(const char * coded_src);
int Base64decode(char * plain_dst, const char *coded_src);

/* aaaack but it's fast and const should make it shared text page. */
static const unsigned char pr2six[256] =
    /* ASCII table */
    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 62, 64, 64, 64, 63,
    52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 64, 64, 64, 64, 64, 64,
    64,  0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14,
    15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 64, 64, 64, 64, 64,
    64, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
    41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 64, 64, 64, 64, 64,
    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64

int Base64decode_len(const char *bufcoded)
    int nbytesdecoded;
    register const unsigned char *bufin;
    register int nprbytes;

    bufin = (const unsigned char *) bufcoded;
    while (pr2six[*(bufin++)] <= 63);

    nprbytes = (bufin - (const unsigned char *) bufcoded) - 1;
    nbytesdecoded = ((nprbytes + 3) / 4) * 3;

    return nbytesdecoded + 1;

int Base64decode(char *bufplain, const char *bufcoded)
    int nbytesdecoded;
    register const unsigned char *bufin;
    register unsigned char *bufout;
    register int nprbytes;

    bufin = (const unsigned char *) bufcoded;
    while (pr2six[*(bufin++)] <= 63);
    nprbytes = (bufin - (const unsigned char *) bufcoded) - 1;
    nbytesdecoded = ((nprbytes + 3) / 4) * 3;

    bufout = (unsigned char *) bufplain;
    bufin = (const unsigned char *) bufcoded;

    while (nprbytes > 4) {
    *(bufout++) =
        (unsigned char) (pr2six[*bufin] << 2 | pr2six[bufin[1]] >> 4);
    *(bufout++) =
        (unsigned char) (pr2six[bufin[1]] << 4 | pr2six[bufin[2]] >> 2);
    *(bufout++) =
        (unsigned char) (pr2six[bufin[2]] << 6 | pr2six[bufin[3]]);
    bufin += 4;
    nprbytes -= 4;

    /* Note: (nprbytes == 1) would be an error, so just ingore that case */
    if (nprbytes > 1) {
    *(bufout++) =
        (unsigned char) (pr2six[*bufin] << 2 | pr2six[bufin[1]] >> 4);
    if (nprbytes > 2) {
    *(bufout++) =
        (unsigned char) (pr2six[bufin[1]] << 4 | pr2six[bufin[2]] >> 2);
    if (nprbytes > 3) {
    *(bufout++) =
        (unsigned char) (pr2six[bufin[2]] << 6 | pr2six[bufin[3]]);

    *(bufout++) = '\0';
    nbytesdecoded -= (4 - nprbytes) & 3;
    return nbytesdecoded;

static const char basis_64[] =

int Base64encode_len(int len)
    return ((len + 2) / 3 * 4) + 1;

int Base64encode(char *encoded, const char *string, int len)
    int i;
    char *p;

    p = encoded;
    for (i = 0; i < len - 2; i += 3) {
    *p++ = basis_64[(string[i] >> 2) & 0x3F];
    *p++ = basis_64[((string[i] & 0x3) << 4) |
                    ((int) (string[i + 1] & 0xF0) >> 4)];
    *p++ = basis_64[((string[i + 1] & 0xF) << 2) |
                    ((int) (string[i + 2] & 0xC0) >> 6)];
    *p++ = basis_64[string[i + 2] & 0x3F];
    if (i < len) {
    *p++ = basis_64[(string[i] >> 2) & 0x3F];
    if (i == (len - 1)) {
        *p++ = basis_64[((string[i] & 0x3) << 4)];
        *p++ = '=';
    else {
        *p++ = basis_64[((string[i] & 0x3) << 4) |
                        ((int) (string[i + 1] & 0xF0) >> 4)];
        *p++ = basis_64[((string[i + 1] & 0xF) << 2)];
    *p++ = '=';

    *p++ = '\0';
    return p - encoded;

 end of base64

const char* GetIPAddress(const char* target_domain) {
    const char* target_ip;
    struct in_addr *host_address;
    struct hostent *raw_list = gethostbyname(target_domain);
    int i = 0;
    for (i; raw_list->h_addr_list[i] != 0; i++) {
        host_address = raw_list->h_addr_list[i];
        target_ip = inet_ntoa(*host_address);
    return target_ip;

char * MailHeader(const char* from, const char* to, const char* subject, const char* mime_type, const char* charset) {

    time_t now;
    char *app_brand = "Codevlog Test APP";
    char* mail_header = NULL;
    char date_buff[26];
    char Branding[6 + strlen(date_buff) + 2 + 10 + strlen(app_brand) + 1 + 1];
    char Sender[6 + strlen(from) + 1 + 1];
    char Recip[4 + strlen(to) + 1 + 1];
    char Subject[8 + 1 + strlen(subject) + 1 + 1];
    char mime_data[13 + 1 + 3 + 1 + 1 + 13 + 1 + strlen(mime_type) + 1 + 1 + 8 + strlen(charset) + 1 + 1 + 2];

    strftime(date_buff, (33), "%a , %d %b %Y %H:%M:%S", localtime(&now));

    sprintf(Branding, "DATE: %s\r\nX-Mailer: %s\r\n", date_buff, app_brand);
    sprintf(Sender, "FROM: %s\r\n", from);
    sprintf(Recip, "To: %s\r\n", to);
    sprintf(Subject, "Subject: %s\r\n", subject);
    sprintf(mime_data, "MIME-Version: 1.0\r\nContent-type: %s; charset=%s\r\n\r\n", mime_type, charset);

    int mail_header_length = strlen(Branding) + strlen(Sender) + strlen(Recip) + strlen(Subject) + strlen(mime_data) + 10;

    mail_header = (char*) malloc(mail_header_length);

    memcpy(&mail_header[0], &Branding, strlen(Branding));
    memcpy(&mail_header[0 + strlen(Branding)], &Sender, strlen(Sender));
    memcpy(&mail_header[0 + strlen(Branding) + strlen(Sender)], &Recip, strlen(Recip));
    memcpy(&mail_header[0 + strlen(Branding) + strlen(Sender) + strlen(Recip)], &Subject, strlen(Subject));
    memcpy(&mail_header[0 + strlen(Branding) + strlen(Sender) + strlen(Recip) + strlen(Subject)], &mime_data, strlen(mime_data));
    return mail_header;

my_bool SendEmail_init(UDF_INIT *initid,UDF_ARGS *arg,char *message){
     if (!(arg->arg_count == 2)) {
        strcpy(message, "Expected two arguments");
        return 1;

    arg->arg_type[0] = STRING_RESULT;// smtp server address
    arg->arg_type[1] = STRING_RESULT;// email body
    initid->ptr = (char*) malloc(2050 * sizeof (char));
    memset(initid->ptr, '\0', sizeof (initid->ptr));
    return 0;

void SendEmail_deinit(UDF_INIT *initid __attribute__((unused))){
    if (initid->ptr) {

char* SendEmail(UDF_INIT *initid, UDF_ARGS *arg,char *result,unsigned long *length, char *is_null,char* error){
   char *header = MailHeader(From_header, TO_header, "Hello Its a test Mail from Codevlog", "text/plain", "US-ASCII");
    int connected_fd = socket(AF_INET, SOCK_STREAM, IPPROTO_IP);
    struct sockaddr_in addr;
    memset(&addr, 0, sizeof (addr));
    addr.sin_family = AF_INET;
    addr.sin_port = htons(25);
    if (inet_pton(AF_INET, GetIPAddress(arg->args[0]), &addr.sin_addr) == 1) {
        connect(connected_fd, (struct sockaddr*) &addr, sizeof (addr));
    if (connected_fd != -1) {
        int recvd = 0;
        const char recv_buff[4768];
        int sdsd;
        sdsd = recv(connected_fd, recv_buff + recvd, sizeof (recv_buff) - recvd, 0);
        recvd += sdsd;

        char buff[1000];
        strcpy(buff, "EHLO "); //"EHLO\r\n"
        strcat(buff, domain);
        strcat(buff, "\r\n");
        send(connected_fd, buff, strlen(buff), 0);
        sdsd = recv(connected_fd, recv_buff + recvd, sizeof (recv_buff) - recvd, 0);
        recvd += sdsd;

        char _cmd2[1000];
        strcpy(_cmd2, "AUTH LOGIN\r\n");
        int dfdf = send(connected_fd, _cmd2, strlen(_cmd2), 0);
        sdsd = recv(connected_fd, recv_buff + recvd, sizeof (recv_buff) - recvd, 0);
        recvd += sdsd;

        char _cmd3[1000];
        Base64encode(&_cmd3, UID, strlen(UID));
        strcat(_cmd3, "\r\n");
        send(connected_fd, _cmd3, strlen(_cmd3), 0);
        sdsd = recv(connected_fd, recv_buff + recvd, sizeof (recv_buff) - recvd, 0);
        recvd += sdsd;

        char _cmd4[1000];
        Base64encode(&_cmd4, PWD, strlen(PWD));
        strcat(_cmd4, "\r\n");
        send(connected_fd, _cmd4, strlen(_cmd4), 0);
        sdsd = recv(connected_fd, recv_buff + recvd, sizeof (recv_buff) - recvd, 0);
        recvd += sdsd;

        char _cmd5[1000];
        strcpy(_cmd5, "MAIL FROM: ");
        strcat(_cmd5, From);
        strcat(_cmd5, "\r\n");
        send(connected_fd, _cmd5, strlen(_cmd5), 0);
        char skip[1000];
        sdsd = recv(connected_fd, skip, sizeof (skip), 0);

        char _cmd6[1000];
        strcpy(_cmd6, "RCPT TO: ");
        strcat(_cmd6, To); //
        strcat(_cmd6, "\r\n");
        send(connected_fd, _cmd6, strlen(_cmd6), 0);
        sdsd = recv(connected_fd, recv_buff + recvd, sizeof (recv_buff) - recvd, 0);
        recvd += sdsd;

        char _cmd7[1000];
        strcpy(_cmd7, "DATA\r\n");
        send(connected_fd, _cmd7, strlen(_cmd7), 0);
        sdsd = recv(connected_fd, recv_buff + recvd, sizeof (recv_buff) - recvd, 0);
        recvd += sdsd;

        send(connected_fd, header, strlen(header), 0);
        send(connected_fd, arg->args[1], strlen(arg->args[1]), 0);
        char _cmd9[1000];
        strcpy(_cmd9, "\r\n.\r\n.");
        send(connected_fd, _cmd9, sizeof (_cmd9), 0);
        sdsd = recv(connected_fd, recv_buff + recvd, sizeof (recv_buff) - recvd, 0);
        recvd += sdsd;

        char _cmd10[1000];
        strcpy(_cmd10, "QUIT\r\n");
        send(connected_fd, _cmd10, sizeof (_cmd10), 0);
        sdsd = recv(connected_fd, recv_buff + recvd, sizeof (recv_buff) - recvd, 0);

        memcpy(initid->ptr, recv_buff, strlen(recv_buff));
        *length = recvd;
    return initid->ptr;

To configure your project go through this video: (Send Email from MySQL on Linux) It will work for any mysql version (5.5, 5.6, 5.7)

I will resolve if any error appear in above code, Just Inform in comment

Error: Tablespace for table xxx exists. Please DISCARD the tablespace before IMPORT

Had exactly the same problem; I'd brew added [email protected] (after previously having 5.5).

The brew defaults for 5.6 are innodb_file_per_table=1 whereas in 5.5 they're innodb_file_per_table=0.

Your existing ibdata1 file (the combined innodb data) will still have references to the tables you're trying to create/drop. Either change innodb_file_per_table back to 0, or delete the ibdata1 data file (this will lose you all your data, so make sure you mysqldump it first or already have an .sql dump).

The other brew [email protected] default that bit me was the lack of a port, so networking was defaulting to unix sockets, and the mysql client kept reporting:

ERROR 2013 (HY000): Lost connection to MySQL server at 'sending authentication information', system error: 32

I added <string>--port=3306</string> to the .plist array, but you could also specify port=3306 in your my.cnf

Run brew services stop [email protected] make your changes then brew services start [email protected]

What is a serialVersionUID and why should I use it?

What is a serialVersionUID and why should I use it?

SerialVersionUID is a unique identifier for each class, JVM uses it to compare the versions of the class ensuring that the same class was used during Serialization is loaded during Deserialization.

Specifying one gives more control, though JVM does generate one if you don't specify. The value generated can differ between different compilers. Furthermore, sometimes you just want for some reason to forbid deserialization of old serialized objects [backward incompatibility], and in this case you just have to change the serialVersionUID.

The javadocs for Serializable say:

the default serialVersionUID computation is highly sensitive to class details that may vary depending on compiler implementations, and can thus result in unexpected InvalidClassExceptions during deserialization.

Therefore, you must declare serialVersionUID because it give us more control.

This article has some good points on the topic.

How to DROP multiple columns with a single ALTER TABLE statement in SQL Server?

For MySQL (ver 5.6), you cannot do multiple column drop with one single drop-statement but rather multiple drop-statements:

mysql> alter table test2 drop column (c1,c2,c3);
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '(c1,c2,c3)' at line 1
mysql> alter table test2 drop column c1,c2,c3;
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'c2,c3' at line 1
mysql> alter table test2 drop column c1, drop column c2, drop c3;
Query OK, 0 rows affected (0.64 sec)
Records: 0  Duplicates: 0  Warnings: 0


BTW, drop <col_name> is shorthanded for drop column <col_name> as you can see from drop c3 above.

R cannot be resolved - Android error

This error cropped up on my x64 Linux Mint installation. It turned out that the result was a failure in the ADB binary, because the ia32-libs package was not installed. Simply running apt-get install ia32-libs and relaunching Eclipse fixed the error.

If your x64 distro does not have ia32-libs, you'll have to go Multiarch.

Check #4 and #5 on this post:

Hope this helps someone.

Filtering a pyspark dataframe using isin by exclusion

df.filter(( != 'a') & ( != 'b'))

How to select first child with jQuery?

Try with: $('.onediv').eq(0)

demo jsBin

From the demo: Other examples of selectors and methods targeting the first LI unside an UL:

.eq() Method: $('li').eq(0)
:eq() selector: $('li:eq(0)')
.first() Method $('li').first()
:first selector: $('li:first')
:first-child selector: $('li:first-child')
:lt() selector:$('li:lt(1)')
:nth-child() selector:$('li:nth-child(1)')

jQ + JS:

Array.slice() Method: $('li').slice(0,1)

you can also use [i] to get the JS HTMLelement index out of the jQuery el. (array) collection like eg:


now that you have the JS element representation you have to use JS native methods eg:

$('li')[0].className = 'active'; // Adds class "active" to the first LI in the DOM

or you can (don't - it's bad design) wrap it back into a jQuery object

$( $('li')[0] ).addClass('active'); // Don't. Use .eq() instead

Android - how to replace part of a string by another string?


I noticed that you commented in 2011 but i thought i should post this answer anyway, in case anyone needs to "replace the original string" and runs into this answer ..

Im using a EditText as an example


 EditText textbox = (EditText) findViewById(;


 String oldText = "hello"
 String newText = "Hi";      
 String textBoxText = textbox.getText().toString();


String returnedString = textBoxText.replace( oldText, newText );



This is untested, but it's just an example of using the returned string to replace the original layouts string with setText() !

Obviously this example requires that you have a EditText with the ID set to your_textboxID

How do I update Ruby Gems from behind a Proxy (ISA-NTLM)

Rather than editing batch files (which you may have to do for other Ruby gems, e.g. Bundler), it's probably better to do this once, and do it properly.

On Windows, behind my corporate proxy, all I had to do was add the HTTP_PROXY environment variable to my system.

  1. Start -> right click Computer -> Properties
  2. Choose "Advanced System Settings"
  3. Click Advanced -> Environment Variables
  4. Create a new System variable named "HTTP_PROXY", and set the Value to your proxy server
  5. Reboot or log out and back in again

Depending on your authentication requirements, the HTTP_PROXY value can be as simple as:


Or more complex as others have pointed out


Python: Remove division decimal

if val % 1 == 0:
    val = int(val)

    val = float(val)

This worked for me.

How it works: if the remainder of the quotient of val and 1 is 0, val has to be an integer and can, therefore, be declared to be int without having to worry about losing decimal numbers.

Compare these two situations:


val = 12.00

if val % 1 == 0:
    val = int(val)
    val = float(val)


In this scenario, the output is 12, because 12.00 divided by 1 has the remainder of 0. With this information we know, that val doesn't have any decimals and we can declare val to be int.


val = 13.58

if val % 1 == 0:
    val = int(val)
    val = float(val)


This time the output is 13.58, because when val is divided by 1 there is a remainder (0.58) and therefore val is declared to be a float.

By just declaring the number to be an int (without testing the remainder) decimal numbers will be cut off.

This way there are no zeros in the end and no other than the zeros will be ignored.

How to delete a file or folder?

Path objects from the Python 3.4+ pathlib module also expose these instance methods:

What is a Java String's default initial value?

There are three types of variables:

  • Instance variables: are always initialized
  • Static variables: are always initialized
  • Local variables: must be initialized before use

The default values for instance and static variables are the same and depends on the type:

  • Object type (String, Integer, Boolean and others): initialized with null
  • Primitive types:
    • byte, short, int, long: 0
    • float, double: 0.0
    • boolean: false
    • char: '\u0000'

An array is an Object. So an array instance variable that is declared but no explicitly initialized will have null value. If you declare an int[] array as instance variable it will have the null value.

Once the array is created all of its elements are assiged with the default type value. For example:

private boolean[] list; // default value is null

private Boolean[] list; // default value is null

once is initialized:

private boolean[] list = new boolean[10]; // all ten elements are assigned to false

private Boolean[] list = new Boolean[10]; // all ten elements are assigned to null (default Object/Boolean value)

Run a batch file with Windows task scheduler

Make sure "Start In" does NOT end with a BACKSLASH.

"pip install unroll": "python egg_info" failed with error code 1

I had the same problem.

The problem was:

pyparsing 2.2 was already installed and my requirements.txt was trying to install pyparsing 2.0.1 which throw this error

Context: I was using virtualenv, and it seems the 2.2 came from my global OS Python site-packages, but even with --no-site-packages flag (now by default in last virtualenv) the 2.2 was still present. Surely because I installed Python from their website and it added Python libraries to my $PATH.

Maybe a pip install --ignore-installed would have worked.

Solution: as I needed to move forwards, I just removed the pyparsing==2.0.1 from my requirements.txt.

Trigger standard HTML5 validation (form) without using submit button?

I know it is an old topic, but when there is a very complex (especially asynchronous) validation process, there is a simple workaround:

<form id="form1">
<input type="button" onclick="javascript:submitIfVeryComplexValidationIsOk()" />
<input type="submit" id="form1_submit_hidden" style="display:none" />
function submitIfVeryComplexValidationIsOk() {
    var form1 = document.forms['form1']
    if (!form1.checkValidity()) {

    if (checkForVeryComplexValidation() === 'Ok') {
    } else {
         alert('form is invalid')

Case insensitive string compare in LINQ-to-SQL

Sometimes value stored in Database could contain spaces so running this could be fail

String.Equals(row.Name, "test", StringComparison.OrdinalIgnoreCase)

Solution to this problems is to remove space then convert its case then select like this

 return db.UsersTBs.Where(x => x.title.ToString().ToLower().Replace(" ",string.Empty).Equals(customname.ToLower())).FirstOrDefault();

Note in this case

customname is value to match with Database value

UsersTBs is class

title is the Database column

getActionBar() returns null



extends AppCompatActivity

then use


jQuery jump or scroll to certain position, div or target on the page from button onclick

I would style a link to look like a button, because that way there is a no-js fallback.

So this is how you could animate the jump using jquery. No-js fallback is a normal jump without animation.

Original example:


$(document).ready(function() {_x000D_
  $(".jumper").on("click", function( e ) {_x000D_
    $("body, html").animate({ _x000D_
      scrollTop: $( $(this).attr('href') ).offset().top _x000D_
    }, 600);_x000D_
#long {_x000D_
  height: 500px;_x000D_
  background-color: blue;_x000D_
<script src=""></script>_x000D_
<!-- Links that trigger the jumping -->_x000D_
<a class="jumper" href="#pliip">Pliip</a>_x000D_
<a class="jumper" href="#ploop">Ploop</a>_x000D_
<div id="long">...</div>_x000D_
<!-- Landing elements -->_x000D_
<div id="pliip">pliip</div>_x000D_
<div id="ploop">ploop</div>

New example with actual button styles for the links, just to prove a point.

Everything is essentially the same, except that I changed the class .jumper to .button and I added css styling to make the links look like buttons.

Button styles example

How to get back Lost phpMyAdmin Password, XAMPP

There is a batch file called resetroot.bat located in the xammp folders 'C:\xampp\mysql' run this and it will delete the phpmyadmin passwords. Then all you need to do is start the MySQL service in xamp and click the admin button.

How to write multiple conditions of if-statement in Robot Framework

Just make sure put single space before and after "and" Keyword..

How to set DialogFragment's width and height?

You can below code to set layout width and height from java.

final AlertDialog alertDialog  = alertDialogBuilder.create();
final WindowManager.LayoutParams WMLP = alertDialog.getWindow().getAttributes();

WMLP.gravity = Gravity.TOP;
WMLP.y = mActionBarHeight;
WMLP.x = getResources().getDimensionPixelSize(R.dimen.unknown_image_width);


PHP case-insensitive in_array function

Say you want to use the in_array, here is how you can make the search case insensitive.

Case insensitive in_array():

foreach($searchKey as $key => $subkey) {

     if (in_array(strtolower($subkey), array_map("strtolower", $subarray)))
        echo "found";


Normal case sensitive:

foreach($searchKey as $key => $subkey) {

if (in_array("$subkey", $subarray))

        echo "found";


Creating a custom JButton in Java

When I was first learning Java we had to make Yahtzee and I thought it would be cool to create custom Swing components and containers instead of just drawing everything on one JPanel. The benefit of extending Swing components, of course, is to have the ability to add support for keyboard shortcuts and other accessibility features that you can't do just by having a paint() method print a pretty picture. It may not be done the best way however, but it may be a good starting point for you.

Edit 8/6 - If it wasn't apparent from the images, each Die is a button you can click. This will move it to the DiceContainer below. Looking at the source code you can see that each Die button is drawn dynamically, based on its value.

alt text
alt text
alt text

Here are the basic steps:

  1. Create a class that extends JComponent
  2. Call parent constructor super() in your constructors
  3. Make sure you class implements MouseListener
  4. Put this in the constructor:

  5. Override these methods:

    public Dimension getPreferredSize()  
    public Dimension getMinimumSize()  
    public Dimension getMaximumSize()
  6. Override this method:

    public void paintComponent(Graphics g)

The amount of space you have to work with when drawing your button is defined by getPreferredSize(), assuming getMinimumSize() and getMaximumSize() return the same value. I haven't experimented too much with this but, depending on the layout you use for your GUI your button could look completely different.

And finally, the source code. In case I missed anything.

Excel is not updating cells, options > formula > workbook calculation set to automatic

the ctrl alt f9 , is the temporary solution , going to options-formula-auto calculate is the right way, that option turned manual, because some shortcut key on being pressed by mistake turns automatic to manual - Add blank item at top of dropdownlist

You could also have a union of the blank select with the select that has content:

select '' value, '' name
select value, name from mytable

Remove all multiple spaces in Javascript and replace with single space

You can also replace without a regular expression.

while(str.indexOf('  ')!=-1)str.replace('  ',' ');

How to prevent page from reloading after form submit - JQuery

The <button> element, when placed in a form, will submit the form automatically unless otherwise specified. You can use the following 2 strategies:

  1. Use <button type="button"> to override default submission behavior
  2. Use event.preventDefault() in the onSubmit event to prevent form submission

Solution 1:

  • Advantage: simple change to markup
  • Disadvantage: subverts default form behavior, especially when JS is disabled. What if the user wants to hit "enter" to submit?

Insert extra type attribute to your button markup:

<button id="button" type="button" value="send" class="btn btn-primary">Submit</button>

Solution 2:

  • Advantage: form will work even when JS is disabled, and respects standard form UI/UX such that at least one button is used for submission

Prevent default form submission when button is clicked. Note that this is not the ideal solution because you should be in fact listening to the submit event, not the button click event:

$(document).ready(function () {
  // Listen to click event on the submit button
  $('#button').click(function (e) {


    var name = $("#name").val();
    var email = $("#email").val();

    $.post("process.php", {
      name: name,
      email: email
    }).complete(function() {

Better variant:

In this improvement, we listen to the submit event emitted from the <form> element:

$(document).ready(function () {
  // Listen to submit event on the <form> itself!
  $('#main').submit(function (e) {


    var name = $("#name").val();
    var email = $("#email").val();

    $.post("process.php", {
      name: name,
      email: email
    }).complete(function() {

Even better variant: use .serialize() to serialize your form, but remember to add name attributes to your input:

The name attribute is required for .serialize() to work, as per jQuery's documentation:

For a form element's value to be included in the serialized string, the element must have a name attribute.

<input type="text" id="name" name="name" class="form-control mb-2 mr-sm-2 mb-sm-0" id="inlineFormInput" placeholder="Jane Doe">
<input type="text" id="email" name="email" class="form-control" id="inlineFormInputGroup" placeholder="[email protected]">

And then in your JS:

$(document).ready(function () {
  // Listen to submit event on the <form> itself!
  $('#main').submit(function (e) {

    // Prevent form submission which refreshes page

    // Serialize data
    var formData = $(this).serialize();

    // Make AJAX request
    $.post("process.php", formData).complete(function() {

How to pass text in a textbox to JavaScript function?

if I have understood correct the question :

<TITLE>Passing values</TITLE>_x000D_
Give a number :<input type="number" id="num"><br>_x000D_
<button onclick="MyFunction(num.value)">Press button...</button>_x000D_
function MyFunction(num) {_x000D_
   document.write("<h1>You gave "+num+"</h1>");_x000D_

Getting XML Node text value with Java DOM

If your XML goes quite deep, you might want to consider using XPath, which comes with your JRE, so you can access the contents far more easily using:

String text = xp.evaluate("//add[@job='351']/tag[position()=1]/text()", 

Full example:

import static org.junit.Assert.assertEquals;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.xpath.XPath;
import javax.xml.xpath.XPathFactory;    
import org.junit.Before;
import org.junit.Test;
import org.w3c.dom.Document;
import org.xml.sax.InputSource;

public class XPathTest {

    private Document document;

    public void setup() throws Exception {
        String xml = "<add job=\"351\"><tag>foobar</tag><tag>foobar2</tag></add>";
        DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
        DocumentBuilder db = dbf.newDocumentBuilder();
        document = db.parse(new InputSource(new StringReader(xml)));

    public void testXPath() throws Exception {
        XPathFactory xpf = XPathFactory.newInstance();
        XPath xp = xpf.newXPath();
        String text = xp.evaluate("//add[@job='351']/tag[position()=1]/text()",
        assertEquals("foobar", text);

redistributable offline .NET Framework 3.5 installer for Windows 8

After several month without real solution for this problem, I suppose that the best solution is to upgrade the application to .NET framework 4.0, which is supported by Windows 8, Windows 10 and Windows 2012 Server by default and it is still available as offline installation for Windows XP.

Understanding ASP.NET Eval() and Bind()

The question was answered perfectly by Darin Dimitrov, but since ASP.NET 4.5, there is now a better way to set up these bindings to replace* Eval() and Bind(), taking advantage of the strongly-typed bindings.

*Note: this will only work if you're not using a SqlDataSource or an anonymous object. It requires a Strongly-typed object (from an EF model or any other class).

This code snippet shows how Eval and Bind would be used for a ListView control (InsertItem needs Bind, as explained by Darin Dimitrov above, and ItemTemplate is read-only (hence they're labels), so just needs an Eval):

<asp:ListView ID="ListView1" runat="server" DataKeyNames="Id" InsertItemPosition="LastItem" SelectMethod="ListView1_GetData" InsertMethod="ListView1_InsertItem" DeleteMethod="ListView1_DeleteItem">
            Title: <asp:TextBox ID="Title" runat="server" Text='<%# Bind("Title") %>'/><br />         
            Description: <asp:TextBox ID="Description" runat="server" TextMode="MultiLine" Text='<%# Bind("Description") %>' /><br />        
            <asp:Button ID="InsertButton" runat="server" Text="Insert" CommandName="Insert" />        
            Title: <asp:Label ID="Title" runat="server" Text='<%#  Eval("Title") %>' /><br />
            Description: <asp:Label ID="Description" runat="server" Text='<%# Eval("Description") %>' /><br />        
            <asp:Button ID="DeleteButton" runat="server" Text="Delete" CommandName="Delete" CausesValidation="false"/>

From ASP.NET 4.5+, data-bound controls have been extended with a new property ItemType, which points to the type of object you're assigning to its data source.

<asp:ListView ItemType="Picture" ID="ListView1" runat="server" ...>

Picture is the strongly type object (from EF model). We then replace:

Bind(property) ->
Eval(property) ->

So this:

<%# Bind("Title") %>      
<%# Bind("Description") %>         
<%#  Eval("Title") %> 
<%# Eval("Description") %>

Would become this:

<%# BindItem.Title %>         
<%# BindItem.Description %>
<%# Item.Title %>
<%# Item.Description %>

Advantages over Eval & Bind:

  • IntelliSense can find the correct property of the object your're working withenter image description here
  • If property is renamed/deleted, you will get an error before page is viewed in browser
  • External tools (requires full versions of VS) will correctly rename item in markup when you rename a property on your object

Source: from this excellent book

How can I implement prepend and append with regular JavaScript?

You can also use unshift() to prepend to a list

What are the differences between WCF and ASMX web services?

Keith Elder nicely compares ASMX to WCF here. Check it out.

Another comparison of ASMX and WCF can be found here - I don't 100% agree with all the points there, but it might give you an idea.

WCF is basically "ASMX on stereoids" - it can be all that ASMX could - plus a lot more!.

ASMX is:

  • easy and simple to write and configure
  • only available in IIS
  • only callable from HTTP

WCF can be:

  • hosted in IIS, a Windows Service, a Winforms application, a console app - you have total freedom
  • used with HTTP (REST and SOAP), TCP/IP, MSMQ and many more protocols

In short: WCF is here to replace ASMX fully.

Check out the WCF Developer Center on MSDN.

Update: link seems to be dead - try this: What Is Windows Communication Foundation?

How to insert an item at the beginning of an array in PHP?

Insert an item in the beginning of an associative array with string/custom key


$array = ['keyOne'=>'valueOne', 'keyTwo'=>'valueTwo'];

$array = array_reverse($array);

$array['newKey'] = 'newValue';

$array = array_reverse($array);


  'newKey' => 'newValue',
  'keyOne' => 'valueOne',
  'keyTwo' => 'valueTwo'

Deleting Elements in an Array if Element is a Certain value VBA

When creating the array, why not just skip over the 0s and save yourself the time of having to worry about them later? As mentioned above, arrays are not well-suited for deletion.

How to use pip with Python 3.x alongside Python 2.x

Please note that on msys2 I've found these commands to be helpful:

$ pacman -S python3-pip
$ pip3 install --upgrade pip
$ pip3 install --user package_name

What is the best way to concatenate two vectors?

All the solutions are correct, but I found it easier just write a function to implement this. like this:

template <class T1, class T2>
void ContainerInsert(T1 t1, T2 t2)
    t1->insert(t1->end(), t2->begin(), t2->end());

That way you can avoid the temporary placement like this:

ContainerInsert(vec, GetSomeVector());

How can I sort one set of data to match another set of data in Excel?

You could also use INDEX MATCH, which is more "powerful" than vlookup. This would give you exactly what you are looking for:

enter image description here

Formatting struct timespec

The following will return an ISO8601 and RFC3339-compliant UTC timestamp, including nanoseconds.

It uses strftime(), which works with struct timespec just as well as with struct timeval because all it cares about is the number of seconds, which both provide. Nanoseconds are then appended (careful to pad with zeros!) as well as the UTC suffix 'Z'.

Example output: 2021-01-19T04:50:01.435561072Z

#include <stdio.h>
#include <time.h>
#include <sys/time.h>

int utc_system_timestamp(char[]);

int main(void) {
    char buf[31];
    printf("%s\n", buf);

// Allocate exactly 31 bytes for buf
int utc_system_timestamp(char buf[]) {
        const int bufsize = 31;
        struct timespec now;
        struct tm tm;
        int retval = clock_gettime(CLOCK_REALTIME, &now);
        gmtime_r(&now.tv_sec, &tm);
        strftime(buf, bufsize, "%Y-%m-%dT%H:%M:%S.", &tm);
        sprintf(buf, "%s%09luZ", buf, now.tv_nsec);
        return retval;

PHP shorthand for isset()?

Update for PHP 7 (thanks shock_gone_wild)

PHP 7 introduces the so called null coalescing operator which simplifies the below statements to:

$var = $var ?? "default";

Before PHP 7

No, there is no special operator or special syntax for this. However, you could use the ternary operator:

$var = isset($var) ? $var : "default";

Or like this:

isset($var) ?: $var = 'default';

Flexbox not giving equal width to elements

There is an important bit that is not mentioned in the article to which you linked and that is flex-basis. By default flex-basis is auto.

From the spec:

If the specified flex-basis is auto, the used flex basis is the value of the flex item’s main size property. (This can itself be the keyword auto, which sizes the flex item based on its contents.)

Each flex item has a flex-basis which is sort of like its initial size. Then from there, any remaining free space is distributed proportionally (based on flex-grow) among the items. With auto, that basis is the contents size (or defined size with width, etc.). As a result, items with bigger text within are being given more space overall in your example.

If you want your elements to be completely even, you can set flex-basis: 0. This will set the flex basis to 0 and then any remaining space (which will be all space since all basises are 0) will be proportionally distributed based on flex-grow.

li {
    flex-grow: 1;
    flex-basis: 0;
    /* ... */

This diagram from the spec does a pretty good job of illustrating the point.

And here is a working example with your fiddle.

jQuery: get parent tr for selected radio button

Try this.

You don't need to prefix attribute name by @ in jQuery selector. Use closest() method to get the closest parent element matching the selector.

$("#MwDataList input[name=selectRadioGroup]:checked").closest('tr');

You can simplify your method like this

function getSelectedRowGuid() {
    return GetRowGuid(
      $("#MwDataList > input:radio[@name=selectRadioGroup]:checked :parent tr"));

closest() - Gets the first element that matches the selector, beginning at the current element and progressing up through the DOM tree.

As a side note, the ids of the elements should be unique on the page so try to avoid having same ids for radio buttons which I can see in your markup. If you are not going to use the ids then just remove it from the markup.

Visual Studio Code Search and Replace with Regular Expressions

For beginners, I wanted to add to the accepted answer, because a couple of subtleties were unclear to me:

To find and modify text (not completely replace),

  1. In the "Find" step, you can use regex with "capturing groups," e.g. your search could be la la la (group1) blah blah (group2), using parentheses.

  2. And then in the "Replace" step, you can refer to the capturing groups via $1, $2 etc.

So, for example, in this case we could find the relevant text with just <h1>.+?<\/h1> (no parentheses), but putting in the parentheses <h1>(.+?)<\/h1> allows us to refer to the sub-match in between them as $1 in the replace step. Cool!


  • To turn on Regex in the Find Widget, click the .* icon, or press Cmd/Ctrl Alt R

  • $0 refers to the whole match

  • Finally, the original question states that the replace should happen "within a document," so you can use the "Find Widget" (Cmd or Ctrl + F), which is local to the open document, instead of "Search", which opens a bigger UI and looks across all files in the project.

JQuery Find #ID, RemoveClass and AddClass


$("#testID #testID2").removeClass("test2").addClass("test3");

Because you have assigned an id to img too, you can simply do this too:


And finally, you can do this too:

$("#testID img").removeClass("test2").addClass("test3");

JavaScript: Collision detection

hittest.js; detect two transparent PNG images (pixel) colliding.

Demo and download link

HTML code

<img id="png-object-1" src="images/object1.png" />
<img id="png-object-2" src="images/object2.png" />

Init function

var pngObject1Element = document.getElementById( "png-object-1" );
var pngObject2Element = document.getElementById( "png-object-2" );

var object1HitTest = new HitTest( pngObject1Element );

Basic usage

if( object1HitTest.toObject( pngObject2Element ) ) {
    // Collision detected

How can I get all sequences in an Oracle database?

You may not have permission to dba_sequences. So you can always just do:

select * from user_sequences;

How to override a JavaScript function

var origParseFloat = parseFloat;
parseFloat = function(str) {
     alert("And I'm in your floats!");
     return origParseFloat(str);

How to find Current open Cursors in Oracle

This could work:

SELECT    sql_text "SQL Query", 
          Count(*) AS "Open Cursors" 
FROM      v$open_cursor 
GROUP BY  sql_text 
HAVING    Count(*) > 2 
ORDER BY  Count(*) DESC; 

How to reverse a singly linked list using only two pointers?

Here is a slightly different, but simple approach in C++11:

#include <iostream>

struct Node{
    Node(): next(NULL){}
    Node *next;
    std::string data;

void printlist(Node* l){
        l = l->next;

void reverse(Node*& l)
    Node* prev = NULL;
        auto next = l->next;
        l->next = prev;
    l = prev;

int main() {
    Node s,t,u,v; = "1"; = "2"; = "3"; = "4"; = &t; = &u; = &v;
    Node* ptr = &s;
    return 0;

Output here

Git status shows files as changed even though contents are the same

For me the issue was a case difference in the file.

I renamed the file and committed the delete, It showed both the upper and lower case versions of the file to be deleted.

After the delete was committed I renamed the file back to its original name and pushed.

Set attribute without value

The attr() function is also a setter function. You can just pass it an empty string.


An empty string will simply create the attribute with no value.

<body data-body>

Reference -

attr( attributeName , value )

How to insert a new line in Linux shell script?

Use this echo statement

 echo -e "Hai\nHello\nTesting\n"

The output is


console.log not working in Angular2 Component (Typescript)

The console.log should be wrapped in a function , the "default" function for every class is its constructor so it should be declared there.

import { Component } from '@angular/core';

  selector: 'hello-console',
    export class App {
     s: string = "Hello2";


How to create a zip file in Java

Java 7 has ZipFileSystem built in, that can be used to create, write and read file from zip file.

Java Doc: ZipFileSystem Provider

Map<String, String> env = new HashMap<>();
// Create the zip file if it doesn't exist
env.put("create", "true");

URI uri = URI.create("jar:file:/codeSamples/zipfs/");

try (FileSystem zipfs = FileSystems.newFileSystem(uri, env)) {
    Path externalTxtFile = Paths.get("/codeSamples/zipfs/SomeTextFile.txt");
    Path pathInZipfile = zipfs.getPath("/SomeTextFile.txt");          
    // Copy a file into the zip file
    Files.copy(externalTxtFile, pathInZipfile, StandardCopyOption.REPLACE_EXISTING); 

Is there a way to use SVG as content in a pseudo element :before or :after

Be careful all of the other answers have some problem in IE.

Lets have this situation - button with prepended icon. All browsers handles this correctly, but IE takes the width of the element and scales the before content to fit it. JSFiddle

#mydiv1 { width: 200px; height: 30px; background: green; }
#mydiv1:before {
    content: url("data:url or /standard/url.svg");

Solution is to set size to before element and leave it where it is:

#mydiv2 { width: 200px; height: 30px; background: green; }
#mydiv2:before {
    content: url("data:url or /standard/url.svg");
    display: inline-block;
    width: 16px; //only one size is alright, IE scales uniformly to fit it

The background-image + background-size solutions works as well, but is little unhandy, since you have to specify the same sizes twice.

The result in IE11:

IE rendering

How do I catch a PHP fatal (`E_ERROR`) error?

There are certain circumstances in which even fatal errors should be caught (you might need to do some clean up before exiting gracefully and don’t just die..).

I have implemented a pre_system hook in my CodeIgniter applications so that I can get my fatal errors through emails, and this helped me finding bugs that were not reported (or were reported after they were fixed, as I already knew about them :)).

Sendemail checks if the error has already been reported so that it does not spam you with known errors multiple times.

class PHPFatalError {

    public function setHandler() {

function handleShutdown() {
    if (($error = error_get_last())) {
        echo "<pre>";
        echo "</pre>";
        $message = ob_get_clean();
        echo '{"status":"error","message":"Internal application error!"}';

LINQ syntax where string value is not null or empty

Problem Statement
It's possible to write LINQ to SQL that gets all rows that have either null or an empty string in a given field, but it's not possible to use string.IsNullOrEmpty to do it, even though many other string methods map to LINQ to SQL. Proposed Solution Allow string.IsNullOrEmpty in a LINQ to SQL where clause so that these two queries have the same result:

var fieldNullOrEmpty =
from item in db.SomeTable
where item.SomeField == null || item.SomeField.Equals(string.Empty)
select item;

var fieldNullOrEmpty2 =
from item in db.SomeTable
where string.IsNullOrEmpty(item.SomeField)
select item;

Other Reading:
1. DevArt
3. StackOverflow Post

Why use 'git rm' to remove a file instead of 'rm'?

If you just use rm, you will need to follow it up with git add <fileRemoved>. git rm does this in one step.

You can also use git rm --cached which will remove the file from the index (staging it for deletion on the next commit), but keep your copy in the local file system.

How can I make Bootstrap 4 columns all the same height?

You can use the new Bootstrap cards:

<link rel="stylesheet" href="" integrity="sha384-rwoIResjU2yc3z8GV/NPeZWAv56rSmLldC3R/AZzGRnGxQQKnKkoFVhFQhNUwEyJ" crossorigin="anonymous">_x000D_
<script src="" integrity="sha384-A7FZj7v+d/sdmMqp/nOQwliLvUsJfDHW+k9Omg/a/EheAdgtzNs3hpfag6Ed950n" crossorigin="anonymous"></script>_x000D_
<script src="" integrity="sha384-DztdAPBWPRXSA/3eYEEUWrWCy7G5KFbe8fFjk5JAIxUYHKkDx6Qin1DkWx51bBrb" crossorigin="anonymous"></script>_x000D_
<script src="" integrity="sha384-vBWWzlZJ8ea9aCX4pEW3rVHjgjt7zpkNpZk+02D9phzyeVkE+jo0ieGizqPLForn" crossorigin="anonymous"></script>_x000D_
<div class="card-group">_x000D_
  <div class="card">_x000D_
    <img class="card-img-top" src="..." alt="Card image cap">_x000D_
    <div class="card-block">_x000D_
      <h4 class="card-title">Card title</h4>_x000D_
      <p class="card-text">This is a wider card with supporting text below as a natural lead-in to additional content. This content is a little bit longer.</p>_x000D_
    <div class="card-footer">_x000D_
      <small class="text-muted">Last updated 3 mins ago</small>_x000D_
  <div class="card">_x000D_
    <img class="card-img-top" src="..." alt="Card image cap">_x000D_
    <div class="card-block">_x000D_
      <h4 class="card-title">Card title</h4>_x000D_
      <p class="card-text">This card has supporting text below as a natural lead-in to additional content.</p>_x000D_
    <div class="card-footer">_x000D_
      <small class="text-muted">Last updated 3 mins ago</small>_x000D_
  <div class="card">_x000D_
    <img class="card-img-top" src="..." alt="Card image cap">_x000D_
    <div class="card-block">_x000D_
      <h4 class="card-title">Card title</h4>_x000D_
      <p class="card-text">This is a wider card with supporting text below as a natural lead-in to additional content. This card has even longer content than the first to show that equal height action.</p>_x000D_
    <div class="card-footer">_x000D_
      <small class="text-muted">Last updated 3 mins ago</small>_x000D_

Link: Click here


iPhone/iOS JSON parsing tutorial

Here's a link to my tutorial, which walks you through :

  • creating a JSON WCF Web Service from scratch (and the problems you'll want to avoid)
  • adapting it to read/write SQL Server data
  • getting an iOS 6 app to use the JSON servies.
  • using the JSON web services with JavaScript

All source code is provided, free of charge. Enjoy.

How do I align a label and a textarea?

You need to put them both in some container element and then apply the alignment on it.

For example:

.formfield * {_x000D_
  vertical-align: middle;_x000D_
<p class="formfield">_x000D_
  <label for="textarea">Label for textarea</label>_x000D_
  <textarea id="textarea" rows="5">Textarea</textarea>_x000D_

HTTP GET Request in Node.js Express

Request and Superagent are pretty good libraries to use.

note: request is deprecated, use at your risk!

Using request:

var request=require('request');

  if(err) //TODO: handle err
  if(res.statusCode === 200 ) //etc
  //TODO Do something with response

How do I get the real .height() of a overflow: hidden or overflow: scroll div?

For more information about .scrollHeight property refer to the docs:

The Element.scrollHeight read-only attribute is a measurement of the height of an element's content, including content not visible on the screen due to overflow. The scrollHeight value is equal to the minimum clientHeight the element would require in order to fit all the content in the viewpoint without using a vertical scrollbar. It includes the element padding but not its margin.

Login failed for user 'DOMAIN\MACHINENAME$'

  1. Change the App Pool Identity to Local System
  2. On SQL Mgmt > Security > Logins
    1. Find NT AUTHORITY\SYSTEM double click
    2. User Mappings > Check your database and give it a role below.
    3. Remember also to create the user data base o security logins with a correct password.

plot is not defined

Change that import to

from matplotlib.pyplot import *

Note that this style of imports (from X import *) is generally discouraged. I would recommend using the following instead:

import matplotlib.pyplot as plt

Type datetime for input parameter in procedure

In this part of your SP:

IF @DateFirst <> '' and @DateLast <> ''
   set @FinalSQL  = @FinalSQL
       + '  or convert (Date,DateLog) >=     ''' + @DateFirst
       + ' and convert (Date,DateLog) <=''' + @DateLast  

you are trying to concatenate strings and datetimes.

As the datetime type has higher priority than varchar/nvarchar, the + operator, when it happens between a string and a datetime, is interpreted as addition, not as concatenation, and the engine then tries to convert your string parts (' or convert (Date,DateLog) >= ''' and others) to datetime or numeric values. And fails.

That doesn't happen if you omit the last two parameters when invoking the procedure, because the condition evaluates to false and the offending statement isn't executed.

To amend the situation, you need to add explicit casting of your datetime variables to strings:

set @FinalSQL  = @FinalSQL
    + '  or convert (Date,DateLog) >=     ''' + convert(date, @DateFirst)
    + ' and convert (Date,DateLog) <=''' + convert(date, @DateLast)

You'll also need to add closing single quotes:

set @FinalSQL  = @FinalSQL
    + '  or convert (Date,DateLog) >=     ''' + convert(date, @DateFirst) + ''''
    + ' and convert (Date,DateLog) <=''' + convert(date, @DateLast) + ''''

How to get main window handle from process id?

As an extension to Hiale's solution, you could provide a different or modified version that supports processes that have multiple main windows.

First, amend the structure to allow storing of multiple handles:

struct handle_data {
    unsigned long process_id;
    std::vector<HWND> handles;

Second, amend the callback function:

BOOL CALLBACK enum_windows_callback(HWND handle, LPARAM lParam)
    handle_data& data = *(handle_data*)lParam;
    unsigned long process_id = 0;
    GetWindowThreadProcessId(handle, &process_id);
    if (data.process_id != process_id || !is_main_window(handle)) {
        return TRUE;
    // change these 2 lines to allow storing of handle and loop again
    return TRUE;   

Finally, amend the returns on the main function:

std::vector<HWD> find_main_window(unsigned long process_id)
    handle_data data;
    data.process_id = process_id;
    EnumWindows(enum_windows_callback, (LPARAM)&data);
    return data.handles;

Links not going back a directory?

You need to give a relative file path of <a href="../index.html">Home</a>

Alternately you can specify a link from the root of your site with <a href="/pages/en/index.html">Home</a>

.. and . have special meanings in file paths, .. means up one directory and . means current directory.

so <a href="index.html">Home</a> is the same as <a href="./index.html">Home</a>

what is the unsigned datatype?

In C and C++

unsigned = unsigned int (Integer type)
signed   = signed int (Integer type)

An unsigned integer containing n bits can have a value between 0 and (2^n-1) , which is 2^n different values.

An unsigned integer is either positive or zero.

Signed integers are stored in a computer using 2's complement.

Angularjs if-then-else construction in expression

I am trying to check if a key exist in an array in angular way and landed here on this question. In my Angularjs 1.4 ternary operator worked like below


hence for the array key exist i did a simple JS check

Solution 1 : {{ array['key'] !== undefined ? array['key'] : 'n/a' }}

Solution 2 : {{ "key" in array ? array['key'] : 'n/a' }}

How do I get the height and width of the Android Navigation Bar programmatically?

In case of Samsung S8 none of the above provided methods were giving proper height of navigation bar so I used the KeyboardHeightProvider keyboard height provider android. And it gave me height in negative values and for my layout positioning I adjusted that value in calculations.

Here is :

import android.content.res.Configuration;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewTreeObserver.OnGlobalLayoutListener;
import android.view.WindowManager.LayoutParams;
import android.widget.PopupWindow;

 * The keyboard height provider, this class uses a PopupWindow
 * to calculate the window height when the floating keyboard is opened and closed. 
public class KeyboardHeightProvider extends PopupWindow {

    /** The tag for logging purposes */
    private final static String TAG = "sample_KeyboardHeightProvider";

    /** The keyboard height observer */
    private KeyboardHeightObserver observer;

    /** The cached landscape height of the keyboard */
    private int keyboardLandscapeHeight;

    /** The cached portrait height of the keyboard */
    private int keyboardPortraitHeight;

    /** The view that is used to calculate the keyboard height */
    private View popupView;

    /** The parent view */
    private View parentView;

    /** The root activity that uses this KeyboardHeightProvider */
    private Activity activity;

     * Construct a new KeyboardHeightProvider
     * @param activity The parent activity
    public KeyboardHeightProvider(Activity activity) {
        this.activity = activity;

        LayoutInflater inflator = (LayoutInflater) activity.getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
        this.popupView = inflator.inflate(R.layout.popupwindow, null, false);

        setSoftInputMode(LayoutParams.SOFT_INPUT_ADJUST_RESIZE | LayoutParams.SOFT_INPUT_STATE_ALWAYS_VISIBLE);

        parentView = activity.findViewById(;


        popupView.getViewTreeObserver().addOnGlobalLayoutListener(new OnGlobalLayoutListener() {

                public void onGlobalLayout() {
                    if (popupView != null) {

     * Start the KeyboardHeightProvider, this must be called after the onResume of the Activity.
     * PopupWindows are not allowed to be registered before the onResume has finished
     * of the Activity.
    public void start() {

        if (!isShowing() && parentView.getWindowToken() != null) {
            setBackgroundDrawable(new ColorDrawable(0));
            showAtLocation(parentView, Gravity.NO_GRAVITY, 0, 0);

     * Close the keyboard height provider, 
     * this provider will not be used anymore.
    public void close() { = null;

     * Set the keyboard height observer to this provider. The 
     * observer will be notified when the keyboard height has changed. 
     * For example when the keyboard is opened or closed.
     * @param observer The observer to be added to this provider.
    public void setKeyboardHeightObserver(KeyboardHeightObserver observer) { = observer;

     * Get the screen orientation
     * @return the screen orientation
    private int getScreenOrientation() {
        return activity.getResources().getConfiguration().orientation;

     * Popup window itself is as big as the window of the Activity. 
     * The keyboard can then be calculated by extracting the popup view bottom 
     * from the activity window height. 
    private void handleOnGlobalLayout() {

        Point screenSize = new Point();

        Rect rect = new Rect();

        // REMIND, you may like to change this using the fullscreen size of the phone
        // and also using the status bar and navigation bar heights of the phone to calculate
        // the keyboard height. But this worked fine on a Nexus.
        int orientation = getScreenOrientation();
        int keyboardHeight = screenSize.y - rect.bottom;

        if (keyboardHeight == 0) {
            notifyKeyboardHeightChanged(0, orientation);
        else if (orientation == Configuration.ORIENTATION_PORTRAIT) {
            this.keyboardPortraitHeight = keyboardHeight; 
            notifyKeyboardHeightChanged(keyboardPortraitHeight, orientation);
        else {
            this.keyboardLandscapeHeight = keyboardHeight; 
            notifyKeyboardHeightChanged(keyboardLandscapeHeight, orientation);

    private void notifyKeyboardHeightChanged(int height, int orientation) {
        if (observer != null) {
            observer.onKeyboardHeightChanged(height, orientation);

    public interface KeyboardHeightObserver {
        void onKeyboardHeightChanged(int height, int orientation);

popupwindow.xml :

<?xml version="1.0" encoding="utf-8"?>

Usage in MainActivity

import android.os.Bundle

 * Created by nileshdeokar on 22/02/2018.
class MainActivity : AppCompatActivity() , KeyboardHeightProvider.KeyboardHeightObserver  {

    private lateinit var keyboardHeightProvider : KeyboardHeightProvider

    override fun onCreate(savedInstanceState: Bundle?) {

        keyboardHeightProvider = KeyboardHeightProvider(this) { keyboardHeightProvider?.start() }

    override fun onKeyboardHeightChanged(height: Int, orientation: Int) {
        // In case of 18:9 - e.g. Samsung S8
        // here you get the height of the navigation bar as negative value when keyboard is closed.
        // and some positive integer when keyboard is opened.

    public override fun onPause() {

    public override fun onResume() {

    public override fun onDestroy() {

For any further help you can have a look at advanced usage of this here.

NPM global install "cannot find module"

I did this in simple way...

  1. Un-Install node from control panel [Windows 7]
  2. Install node again
  3. Install protractor npm install --global --verbose protractor
    Update web driver manager.

works fine for me.

Hope this helps you....

Can someone provide an example of a $destroy event for scopes in AngularJS?

$destroy can refer to 2 things: method and event

1. method - $scope.$destroy

.directive("colorTag", function(){
  return {
    restrict: "A",
    scope: {
      value: "=colorTag"
    link: function (scope, element, attrs) {
      var colors = new App.Colors();
      element.css("background-color", stringToColor(scope.value));
      element.css("color", contrastColor(scope.value));

      // Destroy scope, because it's no longer needed.

2. event - $scope.$on("$destroy")

See @SunnyShah's answer.

TempData keep() vs peek()

Just finished understanding Peek and Keep and had same confusion initially. The confusion arises becauses TempData behaves differently under different condition. You can watch this video which explains the Keep and Peek with demonstration

Tempdata helps to preserve values for a single request and CAN ALSO preserve values for the next request depending on 4 conditions”.

If we understand these 4 points you would see more clarity.Below is a diagram with all 4 conditions, read the third and fourth point which talks about Peek and Keep.

enter image description here

Condition 1 (Not read):- If you set a “TempData” inside your action and if you do not read it in your view then “TempData” will be persisted for the next request.

Condition 2 ( Normal Read) :- If you read the “TempData” normally like the below code it will not persist for the next request.

string str = TempData["MyData"];

Even if you are displaying it’s a normal read like the code below.


Condition 3 (Read and Keep) :- If you read the “TempData” and call the “Keep” method it will be persisted.


Condition 4 ( Peek and Read) :- If you read “TempData” by using the “Peek” method it will persist for the next request.

string str = TempData.Peek("Td").ToString();

Reference :-

Static Vs. Dynamic Binding in Java

Because the compiler knows the binding at compile time. If you invoke a method on an interface, for example, then the compiler can't know and the binding is resolved at runtime because the actual object having a method invoked on it could possible be one of several. Therefore that is runtime or dynamic binding.

Your invocation is bound to the Animal class at compile time because you've specified the type. If you passed that variable into another method somewhere else, noone would know (apart from you because you wrote it) what actual class it would be. The only clue is the declared type of Animal.

nginx: how to create an alias url route?

server {
  root /path/to/root;
  location / {
    # bla bla
  location /demo {
    alias /path/to/root/production/folder/here;

If you need to use try_files inside /demo you'll need to replace alias with a root and do a rewrite because of the bug explained here

How do I "decompile" Java class files?

With AndroChef Java Decompiler you can decompile apk, dex, jar and java class-files. It's simple and easy. AndroChef JD is based on FernFlower. You can evaluate it in 10 free uses.

AndroChef supports Java language features like generics, enums and annotations. According to some studies, AndroChef Java Decompiler is able to decompile 98.04% of Java applications generated with traditional Java compilers - a very high recovery rate. It is simple but powerful tool that allows you to decompile Java and Dalvik bytecode (DEX, APK) into readable Java source.

What is define([ , function ]) in JavaScript?

That's probably a requireJS module definition

Check here for more details

RequireJS is a JavaScript file and module loader. It is optimized for in-browser use, but it can be used in other JavaScript environments, like Rhino and Node. Using a modular script loader like RequireJS will improve the speed and quality of your code.

Hive ParseException - cannot recognize input near 'end' 'string'

You can always escape the reserved keyword if you still want to make your query work!!

Just replace end with `end`

Here is the list of reserved keywords

CREATE EXTERNAL TABLE moveProjects (cid string, `end` string, category string)
STORED BY 'org.apache.hadoop.hive.dynamodb.DynamoDBStorageHandler'
TBLPROPERTIES ("" = "Projects",
    "dynamodb.column.mapping" = "cid:cid,end:end,category:category");

Getting HTML elements by their attribute names

You can get attribute using javascript,



var wrap = document.getElementById("wrap");
var myattr = wrap.getAttribute("title");


How can I suppress column header output for a single SQL statement?

Invoke mysql with the -N (the alias for -N is --skip-column-names) option:

mysql -N ...
use testdb;
select * from names;

|    1 | pete  |
|    2 | john  |
|    3 | mike  |
3 rows in set (0.00 sec)

Credit to ErichBSchulz for pointing out the -N alias.

To remove the grid (the vertical and horizontal lines) around the results use -s (--silent). Columns are separated with a TAB character.

mysql -s ...
use testdb;
select * from names;

id  name
1   pete
2   john
3   mike

To output the data with no headers and no grid just use both -s and -N.

mysql -sN ...

How to use conditional breakpoint in Eclipse?

1. Create a class

public class Test {

 public static void main(String[] args) {
    // TODO Auto-generated method stub
     String s[] = {"app","amm","abb","akk","all"};

 public static void doForAllTabs(String[] tablist){
     for(int i = 0; i<tablist.length;i++){

2. Right click on left side of System.out.println(tablist[i]); in Eclipse --> select Toggle Breakpoint

3. Right click on toggle point --> select Breakpoint properties

4. Check the Conditional Check Box --> write tablist[i].equalsIgnoreCase("amm") in text field --> Click on OK

5. Right click on class --> Debug As --> Java Application

JavaScript alert box with timer

If you are looking for an alert that dissapears after an interval you could try the jQuery UI Dialog widget.

Force index use in Oracle

If you think the performance of the query will be better using the index, how could you force the query to use the index?

First you would of course verify that the index gave a better result for returning the complete data set, right?

The index hint is the key here, but the more up to date way of specifying it is with the column naming method rather than the index naming method. In your case you would use:

select /*+ index(table_name (column_having_index)) */ *
from   table_name
where  column_having_index="some value"; 

In more complex cases you might ...

select /*+ index(t (t.column_having_index)) */ *
from   my_owner.table_name t,
where  t.column_having_index="some value"; 

With regard to composite indexes, I'm not sure that you need to specify all columns, but it seems like a good idea. See the docs here on multiple index_specs and use of index_combine for multiple indexes, and here for the specification of multiple columns in the index_spec.

Copy multiple files with Ansible

Use the following source code for copy multiple files on your client machine.

 - name: Copy data to the client machine
   hosts: hostname
   become_method: sudo
   become_user: root
   become: true
     # Copy twice as sometimes files get skipped (mostly only one file skipped from a folder if the folder does not exist)
     - name: Copy UFO-Server 
         src: "source files path"
         dest: "destination file path"
         owner: root
         group: root
         mode: 0644
         backup: yes
       ignore_errors: true


If you are passing multiple paths by using variable then

src: "/root/{{ item }}"

If you are passing path by using a variable for different items then

src: "/root/{{ item.source_path }}"

Iteration ng-repeat only X times in AngularJs

in the html :

<div ng-repeat="t in getTimes(4)">text</div>

and in the controller :

     return new Array(n);


with angularjs > 1.2.x

<div ng-repeat="t in getTimes(4) track by $index">TEXT</div>

How does ApplicationContextAware work in Spring?

Spring source code to explain how ApplicationContextAware work
when you use ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
In AbstractApplicationContext class,the refresh() method have the following code:

// Prepare the bean factory for use in this context.

enter this method,beanFactory.addBeanPostProcessor(new ApplicationContextAwareProcessor(this)); will add ApplicationContextAwareProcessor to AbstractrBeanFactory.

protected void prepareBeanFactory(ConfigurableListableBeanFactory beanFactory) {
        // Tell the internal bean factory to use the context's class loader etc.
        beanFactory.setBeanExpressionResolver(new StandardBeanExpressionResolver(beanFactory.getBeanClassLoader()));
        beanFactory.addPropertyEditorRegistrar(new ResourceEditorRegistrar(this, getEnvironment()));
        // Configure the bean factory with context callbacks.
        beanFactory.addBeanPostProcessor(new ApplicationContextAwareProcessor(this));

When spring initialize bean in AbstractAutowireCapableBeanFactory, in method initializeBean,call applyBeanPostProcessorsBeforeInitialization to implement the bean post process. the process include inject the applicationContext.

    public Object applyBeanPostProcessorsBeforeInitialization(Object existingBean, String beanName)
            throws BeansException {
        Object result = existingBean;
        for (BeanPostProcessor beanProcessor : getBeanPostProcessors()) {
            result = beanProcessor.postProcessBeforeInitialization(result, beanName);
            if (result == null) {
                return result;
        return result;

when BeanPostProcessor implement Objectto execute the postProcessBeforeInitialization method,for example ApplicationContextAwareProcessor that added before.

private void invokeAwareInterfaces(Object bean) {
        if (bean instanceof Aware) {
            if (bean instanceof EnvironmentAware) {
                ((EnvironmentAware) bean).setEnvironment(this.applicationContext.getEnvironment());
            if (bean instanceof EmbeddedValueResolverAware) {
                ((EmbeddedValueResolverAware) bean).setEmbeddedValueResolver(
                        new EmbeddedValueResolver(this.applicationContext.getBeanFactory()));
            if (bean instanceof ResourceLoaderAware) {
                ((ResourceLoaderAware) bean).setResourceLoader(this.applicationContext);
            if (bean instanceof ApplicationEventPublisherAware) {
                ((ApplicationEventPublisherAware) bean).setApplicationEventPublisher(this.applicationContext);
            if (bean instanceof MessageSourceAware) {
                ((MessageSourceAware) bean).setMessageSource(this.applicationContext);
            if (bean instanceof ApplicationContextAware) {
                ((ApplicationContextAware) bean).setApplicationContext(this.applicationContext);

how to check the dtype of a column in python pandas

In pandas 0.20.2 you can do:

from pandas.api.types import is_string_dtype
from pandas.api.types import is_numeric_dtype

>>>> True

>>>> True

So your code becomes:

for y in agg.columns:
    if (is_string_dtype(agg[y])):
    elif (is_numeric_dtype(agg[y])):

What does the symbol \0 mean in a string-literal?

What is the length of str array, and with how much 0s it is ending?

Let's find out:

int main() {
  char str[] = "Hello\0";
  int length = sizeof str / sizeof str[0];
  // "sizeof array" is the bytes for the whole array (must use a real array, not
  // a pointer), divide by "sizeof array[0]" (sometimes sizeof *array is used)
  // to get the number of items in the array
  printf("array length: %d\n", length);
  printf("last 3 bytes: %02x %02x %02x\n",
         str[length - 3], str[length - 2], str[length - 1]);
  return 0;

How can I install Apache Ant on Mac OS X?

To get Ant running on your Mac in 5 minutes, follow these steps.

Open up your terminal.

Perform these commands in order:

/usr/bin/ruby -e "$(curl -fsSL"

brew install ant

If you don't have Java installed yet, you will get the following error: "Error: An unsatisfied requirement failed this build." Run this command next: brew cask install java to fix this.

The installation will resume.

Check your version of by running this command:

ant -version

And you're ready to go!

SQL Server stored procedure parameters

@TaskName varchar(50),
-- SP Logic

Procedure Calling

DECLARE @return_value nvarchar(50)

EXEC  @return_value = GetTaskEvents
        @TaskName = 'TaskName',
        @Id =2  

SELECT  'Return Value' = @return_value

How to convert a hex string to hex number

Use format string

intNum = 123
print "0x%x"%(intNum)

or hex function.

intNum = 123
print hex(intNum)

How to use mongoimport to import csv

I use this on mongoimport shell

mongoimport --db db_name --collection collection_name --type csv --file C:\\Your_file_path\target_file.csv --headerline

type can choose csv/tsv/json But only csv/tsv can use --headerline

You can read more on the offical doc.

What is lazy loading in Hibernate?

In layman's language, it is like you are making a cake and you will need 5-10 ingredients from fridge. You have two options, get all ingredients from fridge and put it on your kitchen platform, or bring the item you want when you need.

Similarly, in eager loading, you fetch all information about bean and its related classes (not child or is-a relation but has a relationship, i.e. cake has flour, has milk, has cream etc), and in case of lazy loading, first you bring only its identifier and values that are coming from same table (necessary ingredients that first you will need in your bowl in case of cake). All information that is coming from other tables will be fetched as and when required/used.

get current page from url

Path.GetFileName( Request.Url.AbsolutePath )

How can I select records ONLY from yesterday?

trunc(tran_date) = trunc(sysdate -1)

Check for file exists or not in sql server?

Try the following code to verify whether the file exist. You can create a user function and use it in your stored procedure. modify it as you need:


 DECLARE @fileFullPath NVARCHAR(100)

 SELECT @Filename = N'LogiSetup.log'
 SELECT @fileFullPath = N'C:\LogiSetup.log'

create table #dir

(output varchar(2000))

SELECT @cmd = 'dir ' + @fileFullPath     

insert into #dir    

exec master.dbo.xp_cmdshell @cmd

--Select * from #dir

-- This is risky, as the fle path itself might contain the filename
if exists (Select * from #dir where output like '%'+ @Filename +'%')

              Print 'File found'    
              --Add code you want to run if file exists    
              Print 'No File Found'    
              --Add code you want to run if file does not exists    

drop table #dir

Twitter API - Display all tweets with a certain hashtag?

UPDATE for v1.1:

Rather than giving q="search_string" give it q="hashtag" in URL encoded form to return results with HASHTAG ONLY. So your query would become:


%23 is URL encoded form of #. Try the link out in your browser and it should work.

You can optimize the query by adding since_id and max_id parameters detailed here. Hope this helps !

Note: Search API is now a OAUTH authenticated call, so please include your access_tokens to the above call


Twitter Search doc link:

How to convert image into byte array and byte array to base64 String in android?

here is another solution...

System.IO.Stream st = new System.IO.StreamReader (picturePath).BaseStream;
byte[] buffer = new byte[4096];

System.IO.MemoryStream m = new System.IO.MemoryStream ();
while (st.Read (buffer,0,buffer.Length) > 0) {
    m.Write (buffer, 0, buffer.Length);
imgView.Tag = m.ToArray ();
st.Close ();
m.Close ();

hope it helps!

Tensorflow installation error: not a supported wheel on this platform

This may mean that you are installing the wrong pre-build binary

since my CPU on Ubuntu 18.04 my download url was:

as it can be found on this github page:

pip install --ignore-installed --upgrade <LOCAL PATH / BINARY-URL>

resolved the issue for me.

How to make flutter app responsive according to different screen size?

You can take a percentage of the width or height as input for scale size.

fontSize: MediaQuery.of(_ctxt).size.height * 0.065

Where the multiplier at the end has a value that makes the Text look good for the active emulator.

Below is how I set it up so all the scaled dimensions are centralized in one place. This way you can adjust them easily and quickly rerun with Hot Reload without having to look for the Media.of() calls throughout the code.

  1. Create the file to store all the mappings appScale.dart

    class AppScale {
      BuildContext _ctxt;
      double get labelDim => scaledWidth(.04);
      double get popupMenuButton => scaledHeight(.065); 

      double scaledWidth(double widthScale) {
        return MediaQuery.of(_ctxt).size.width * widthScale;
      double scaledHeight(double heightScale) {
        return MediaQuery.of(_ctxt).size.height * heightScale;

  1. Then reference that where ever you need the scaled value

    AppScale _scale = AppScale(context);

    // ... 

    Widget label1 = Text(
      "Some Label",
      style: TextStyle(fontSize: _scale.labelDim),

Thanks to answers in this post

Animate background image change with jQuery

Have a look at this jQuery plugin from OvalPixels.

It may do the trick.

How can I represent a range in Java?

You could use java.time.temporal.ValueRange which accepts long and would also work with int:

int a = 2147;

//Use java 8 java.time.temporal.ValueRange. The range defined
//is inclusive of both min and max 
ValueRange range = ValueRange.of(0, 2147483647);

if(range.isValidValue(a)) {
    System.out.println("in range");
}else {
    System.out.println("not in range");

Easiest way to split a string on newlines in .NET?

You should be able to split your string pretty easily, like so:


I have filtered my Excel data and now I want to number the rows. How do I do that?

Try this:

On first row set value 1 (e.g cell A1)

on next row set: =A1+1

Finally autocomplete the remaining rows

Fix CSS hover on iPhone/iPad/iPod

The hover pseudo class only functions on iOS when applied to a link tag. They do that because there is no hover on a touch device reall. It acts more like the active class. So they can't have one unless its a link going somewhere for usability reasons. Change your div to a link tag and you will have no problem.

How to set opacity in parent div and not affect in child div?

You can't do that, unless you take the child out of the parent and place it via positioning.

The only way I know and it actually works, is to use a translucid image (.png with transparency) for the parent's background. The only disavantage is that you can't control the opacity via CSS, other than that it works!

How to reformat JSON in Notepad++?

I'm using the JSON Viewer plug-in with NPP 5.9 and it seems to work well.

When to use setAttribute vs .attribute= in JavaScript?

This is very good discussion. I had one of those moments when I wished or lets say hoped (successfully that I might add) to reinvent the wheel be it a square one. Any ways above is good discussion, so any one coming here looking for what is the difference between Element property and attribute. here is my penny worth and I did have to find it out hard way. I would keep it simple so no extraordinary tech jargon.

suppose we have a variable calls 'A'. what we are used to is as following.

Below will throw an error because simply it put its is kind of object that can only have one property and that is singular left hand side = singular right hand side object. Every thing else is ignored and tossed out in bin.

let A = 'f';
A.b =2;

who has decided that it has to be singular = singular. People who make JavaScript and html standards and thats how engines work.

Lets change the example.

let A = {};
A.b =2;

This time it works ..... because we have explicitly told it so and who decided we can tell it in this case but not in previous case. Again people who make JavaScript and html standards.

I hope we are on this lets complicate it further

let A = {};
A.attribute ={};
console.log(A.attribute.b); // will work

console.log(A.b); // will not work

What we have done is tree of sorts level 1 then sub levels of non-singular object. Unless you know what is where and and call it so it will work else no.

This is what goes on with HTMLDOM when its parsed and painted a DOm tree is created for each and every HTML ELEMENT. Each has level of properties per say. Some are predefined and some are not. This is where ID and VALUE bits come on. Behind the scene they are mapped on 1:1 between level 1 property and sun level property aka attributes. Thus changing one changes the other. This is were object getter ans setter scheme of things plays role.

let A = {
attribute :{
getAttributes: function (n) {
    return this.attribute[n];
setAttributes: function (n,nn){
this.attribute[n] = nn;
if(this[n]) this[n] = nn;
}; = 5;




This is the point as shown above ELEMENTS has another set of so called property list attributes and it has its own main properties. there some predefined properties between the two and are mapped as 1:1 e.g. ID is common to every one but value is not nor is src. when the parser reaches that point it simply pulls up dictionary as to what to when such and such are present.

All elements have properties and attributes and some of the items between them are common. What is common in one is not common in another.

In old days of HTML3 and what not we worked with html first then on to JS. Now days its other way around and so has using inline onlclick become such an abomination. Things have moved forward in HTML5 where there are many property lists accessible as collection e.g. class, style. In old days color was a property now that is moved to css for handling is no longer valid attribute.

Element.attributes is sub property list with in Element property.

Unless you could change the getter and setter of Element property which is almost high unlikely as it would break hell on all functionality is usually not writable off the bat just because we defined something as A.item does not necessarily mean Js engine will also run another line of function to add it into Element.attributes.item.

I hope this gives some headway clarification as to what is what. Just for the sake of this I tried Element.prototype.setAttribute with custom function it just broke loose whole thing all together, as it overrode native bunch of functions that set attribute function was playing behind the scene.

How do I assign a null value to a variable in PowerShell?

Use $dec = $null

From the documentation:

$null is an automatic variable that contains a NULL or empty value. You can use this variable to represent an absent or undefined value in commands and scripts.

PowerShell treats $null as an object with a value, that is, as an explicit placeholder, so you can use $null to represent an empty value in a series of values.

C++ Singleton design pattern

Has anyone mentioned std::call_once and std::once_flag? Most other approaches - including double checked locking - are broken.

One major problem in singleton pattern implementation is safe initialization. The only safe way is to guard the initialization sequence with synchronizing barriers. But those barriers themselves need to be safely initiated. std::once_flag is the mechanism to get guaranteed safe initialization.

SQL Server Insert if not exists

I would use a merge:

create PROCEDURE [dbo].[EmailsRecebidosInsert]
  (@_DE nvarchar(50),
   @_ASSUNTO nvarchar(50),
   @_DATA nvarchar(30) )
   with data as (select @_DE as de, @_ASSUNTO as assunto, @_DATA as data)
   merge EmailsRecebidos t
   using data s
      on =
     and s.assunte = t.assunto
     and =
    when not matched by target
    then insert (de, assunto, data) values (, s.assunto,;

How to fix "Headers already sent" error in PHP

Generally this error arise when we send header after echoing or printing. If this error arise on a specific page then make sure that page is not echoing anything before calling to start_session().

Example of Unpredictable Error:

 <?php //a white-space before <?php also send for output and arise error

//your page content

One more example:

includes 'functions.php';
?> <!-- This new line will also arise error -->

//your page content

Conclusion: Do not output any character before calling session_start() or header() functions not even a white-space or new-line

Find the 2nd largest element in an array with minimum number of comparisons

A good way with O(1) time complexity would be to use a max-heap. Call the heapify twice and you have the answer.

How to hide columns in HTML table?

.hideFullColumn tr > .hidecol_x000D_

use .hideFullColumn in table and .hidecol in th.You don't need to add class in td individually as it will be problem because index may not be in mind of each td.

Get specific objects from ArrayList when objects were added anonymously?

As per your question requirement , I would like to suggest that Map will solve your problem very efficient and without any hassle.

In Map you can give the name as key and your original object as value.

  Map<String,Cave> myMap=new HashMap<String,Cave>();

python socket.error: [Errno 98] Address already in use

There is obviously another process listening on the port. You might find out that process by using the following command:

$ lsof -i :8000

or change your tornado app's port. tornado's error info not Explicitly on this.

Setting PATH environment variable in OSX permanently

I've found that there are some files that may affect the $PATH variable in macOS (works for me, 10.11 El Capitan), listed below:

  1. As the top voted answer said, vi /etc/paths, which is recommended from my point of view.

  2. Also don't forget the /etc/paths.d directory, which contains files may affect the $PATH variable, set the git and mono-command path in my case. You can ls -l /etc/paths.d to list items and rm /etc/paths.d/path_you_dislike to remove items.

  3. If you're using a "bash" environment (the default, for example), you should check out ~/.bash_profile or ~/.bashrc. There may be not that file yet, but these two files have effects on the $PATH.

  4. If you're using a "zsh" environment (Oh-My-Zsh, for example), you should check out ~./zshrc instead of ~/.bash* thing.

And don't forget to restart all the terminal windows, then echo $PATH. The $PATH string will be PATH_SET_IN_3&4:PATH_SET_IN_1:PATH_SET_IN_2.

Noticed that the first two ways (/etc/paths and /etc/path.d) is in / directory which will affect all the accounts in your computer while the last two ways (~/.bash* or ~/.zsh*) is in ~/ directory (aka, /Users/yourusername/) which will only affect your account settings.

Read more: Mac OS X: Set / Change $PATH Variable - nixCraft

does linux shell support list data structure?

It supports lists, but not as a separate data structure (ignoring arrays for the moment).

The for loop iterates over a list (in the generic sense) of white-space separated values, regardless of how that list is created, whether literally:

for i in 1 2 3; do
    echo "$i"

or via parameter expansion:

listVar="1 2 3"
for i in $listVar; do
    echo "$i"

or command substitution:

for i in $(echo 1; echo 2; echo 3); do
    echo "$i"

An array is just a special parameter which can contain a more structured list of value, where each element can itself contain whitespace. Compare the difference:

array=("item 1" "item 2" "item 3")
for i in "${array[@]}"; do   # The quotes are necessary here
    echo "$i"

list='"item 1" "item 2" "item 3"'
for i in $list; do
    echo $i
for i in "$list"; do
    echo $i
for i in ${array[@]}; do
    echo $i

Java way to check if a string is palindrome

Using reverse is overkill because you don't need to generate an extra string, you just need to query the existing one. The following example checks the first and last characters are the same, and then walks further inside the string checking the results each time. It returns as soon as s is not a palindrome.

The problem with the reverse approach is that it does all the work up front. It performs an expensive action on a string, then checks character by character until the strings are not equal and only then returns false if it is not a palindrome. If you are just comparing small strings all the time then this is fine, but if you want to defend yourself against bigger input then you should consider this algorithm.

boolean isPalindrome(String s) {
  int n = s.length();
  for (int i = 0; i < (n/2); ++i) {
     if (s.charAt(i) != s.charAt(n - i - 1)) {
         return false;

  return true;

java.time.format.DateTimeParseException: Text could not be parsed at index 21

The default parser can parse your input. So you don't need a custom formatter and

String dateTime = "2012-02-22T02:06:58.147Z";
ZonedDateTime d = ZonedDateTime.parse(dateTime);

works as expected.

Exception in thread "main" java.util.NoSuchElementException

You close the second Scanner which closes the underlying InputStream, therefore the first Scanner can no longer read from the same InputStream and a NoSuchElementException results.

The solution: For console apps, use a single Scanner to read from

Aside: As stated already, be aware that Scanner#nextInt does not consume newline characters. Ensure that these are consumed before attempting to call nextLine again by using Scanner#newLine().

See: Do not create multiple buffered wrappers on a single InputStream

How to determine whether a year is a leap year?

The whole formula can be contained in a single expression:

def is_leap_year(year):
    return (year % 4 == 0 and year % 100 != 0) or year % 400 == 0

print n, " is a leap year" if is_leap_year(n) else " is not a leap year"

Add ArrayList to another ArrayList in java

Wouldn't it just be a case of:

ArrayList<ArrayList<String>> outer = new ArrayList<ArrayList<String>>();
ArrayList<String> nodeList = new ArrayList<String>();

// Fill in nodeList here...


Repeat as necesary.

This should return you a list in the format you specified.

How to check if a string contains text from an array of substrings in JavaScript?

substringsArray.every(substring=>yourBigString.indexOf(substring) === -1)

For full support ;)

What is a Python egg?

"Egg" is a single-file importable distribution format for Python-related projects.

"The Quick Guide to Python Eggs" notes that "Eggs are to Pythons as Jars are to Java..."

Eggs actually are richer than jars; they hold interesting metadata such as licensing details, release dependencies, etc.

Android: How to use webcam in emulator?


In Android Studio AVD:

  1. Open AVD Manager:

AVD menu

  1. Add/Edit AVD:

Specific AVD strip

  1. Click Advanced Settings in the bottom of the screen:

AVD Advanced Settings

  1. Set your camera of choice as the front/back cameras:

AVD Camera Settings

Alternative to header("Content-type: text/xml");

Now I see what you are doing. You cannot send output to the screen then change the headers. If you are trying to create an XML file of map marker and download them to display, they should be in separate files.

Take this

function parseToXML($htmlStr)
return $xmlStr;
// Opens a connection to a MySQL server
$connection=mysql_connect (localhost, $username, $password);
if (!$connection) {
  die('Not connected : ' . mysql_error());
// Set the active MySQL database
$db_selected = mysql_select_db($database, $connection);
if (!$db_selected) {
  die ('Can\'t use db : ' . mysql_error());
// Select all the rows in the markers table
$query = "SELECT * FROM markers WHERE 1";
$result = mysql_query($query);
if (!$result) {
  die('Invalid query: ' . mysql_error());
header("Content-type: text/xml");
// Start XML file, echo parent node
echo '<markers>';
// Iterate through the rows, printing XML nodes for each
while ($row = @mysql_fetch_assoc($result)){
  echo '<marker ';
  echo 'name="' . parseToXML($row['name']) . '" ';
  echo 'address="' . parseToXML($row['address']) . '" ';
  echo 'lat="' . $row['lat'] . '" ';
  echo 'lng="' . $row['lng'] . '" ';
  echo 'type="' . $row['type'] . '" ';
  echo '/>';
// End XML file
echo '</markers>';

and place it in phpsqlajax_genxml.php so your javascript can download the XML file. You are trying to do too many things in the same file.

Selecting a row of pandas series/dataframe by integer index

you can loop through the data frame like this .

for ad in range(1,dataframe_c.size):

How to link to apps on the app store

Creating a link could become a complex issue when supporting multiple OS and multiple platform. For example the WebObjects isn't supported on iOS 7 (some of them), some links you create would open another country store then the user's etc.

There is an open source library called iLink that could help you.

There advantages of this library is that the links would be found and created at run time (the library would check the app ID and the OS it is running on and would figure out what link should be created). The best point in this is that you don't need to configure almost anything before using it so that is error free and would work always. That's great also if you have few targets on same project so you don't have to remember which app ID or link to use. This library also would prompt the user to upgrade the app if there is a new version on the store (this is built in and you turn this off by a simple flag) directly pointing to the upgrade page for the app if user agrees.

Copy the 2 library files to your project (iLink.h & iLink.m).

On your appDelegate.m:

#import "iLink.h"

+ (void)initialize
    //configure iLink
    [iLink sharedInstance].globalPromptForUpdate = YES; // If you want iLink to prompt user to update when the app is old.

and on the place you want to open the rating page for example just use:

[[iLink sharedInstance] iLinkOpenAppPageInAppStoreWithAppleID: YOUR_PAID_APP_APPLE_ID]; // You should find YOUR_PAID_APP_APPLE_ID from iTunes Connect 

Don't forget to import iLink.h on the same file.

There is a very good doc for the whole library there and an example projects for iPhone and for Mac.

What's the proper way to compare a String to an enum value?

public class Main {

    enum Vehical{

    public static void main(String[] args){

      String vehicalType = "CAR";

            System.out.println("The provider is Car");

     String vehical_Type = "BUS";

            System.out.println("The provider is Bus");


How to transfer data from JSP to servlet when submitting HTML form

Well, there are plenty of database tutorials online for java (what you're looking for is called JDBC). But if you are using plain servlets, you will have a class that extends HttpServlet and inside it you will have two methods that look like

public void doPost(HttpServletRequest req, HttpServletResponse resp){



public void doGet(HttpServletRequest req, HttpServletResponse resp){


One of them is called to handle GET operations and another is used to handle POST operations. You will then use the HttpServletRequest object to get the parameters that were passed as part of the form like so:

String name = req.getParameter("name");

Then, once you have the data from the form, it's relatively easy to add it to a database using a JDBC tutorial that is widely available on the web. I also suggest searching for a basic Java servlet tutorial to get you started. It's very easy, although there are a number of steps that need to be configured correctly.

JavaScript null check

An “undefined variable” is different from the value undefined.

An undefined variable:

var a;
alert(b); // ReferenceError: b is not defined

A variable with the value undefined:

var a;
alert(a); // Alerts “undefined”

When a function takes an argument, that argument is always declared even if its value is undefined, and so there won’t be any error. You are right about != null followed by !== undefined being useless, though.

Conda command is not recognized on Windows 10

case #1 You should set 3 path:


It will solve problem:

C:\WINDOWS\system32>conda update conda
Solving environment: failed

CondaHTTPError: HTTP 000 CONNECTION FAILED for url <>
Elapsed: -

case #2 Also you can use Anaconda Promd (for Win10) instead CLI (cmd.exe)

Counting array elements in Python

len is a built-in function that calls the given container object's __len__ member function to get the number of elements in the object.

Functions encased with double underscores are usually "special methods" implementing one of the standard interfaces in Python (container, number, etc). Special methods are used via syntactic sugar (object creation, container indexing and slicing, attribute access, built-in functions, etc.).

Using obj.__len__() wouldn't be the correct way of using the special method, but I don't see why the others were modded down so much.

TLS 1.2 not working in cURL

I has similar problem in context of Stripe:

Error: Stripe no longer supports API requests made with TLS 1.0. Please initiate HTTPS connections with TLS 1.2 or later. You can learn more about this at

Forcing TLS 1.2 using CURL parameter is temporary solution or even it can't be applied because of lack of room to place an update. By default TLS test function showed following configuration:

SSL version: NSS/3.21 Basic ECC
SSL version number: 0
TLS test (default): TLS 1.0
TLS test (TLS_v1): TLS 1.2
TLS test (TLS_v1_2): TLS 1.2

I updated libraries using following command:

yum update nss curl openssl

and then saw this:

SSL version: NSS/3.21 Basic ECC
SSL version number: 0
TLS test (default): TLS 1.2
TLS test (TLS_v1): TLS 1.2
TLS test (TLS_v1_2): TLS 1.2

Please notice that default TLS version changed to 1.2! That globally solved problem. This will help PayPal users too: (update before end of June 2017)

Expected linebreaks to be 'LF' but found 'CRLF' linebreak-style

The same situation occurred when I was using VSCode with eslint. If you use VSCode,

1 - Click area that name can be both LF or CRLF where at the bottom right of the VScode.

2 - Select LF from the drop-down menu.

That's worked for me.

enter image description here

Can you have a <span> within a <span>?

Yes. You can have a span within a span. Your problem stems from something else.

Convert INT to FLOAT in SQL

In oracle db there is a trick for casting int to float (I suppose, it should also work in mysql):

select myintfield + 0.0 as myfloatfield from mytable

While @Heximal's answer works, I don't personally recommend it.

This is because it uses implicit casting. Although you didn't type CAST, either the SUM() or the 0.0 need to be cast to be the same data-types, before the + can happen. In this case the order of precedence is in your favour, and you get a float on both sides, and a float as a result of the +. But SUM(aFloatField) + 0 does not yield an INT, because the 0 is being implicitly cast to a FLOAT.

I find that in most programming cases, it is much preferable to be explicit. Don't leave things to chance, confusion, or interpretation.

If you want to be explicit, I would use the following.

CAST(SUM( AS FLOAT) * cp.price
-- using MySQL CAST FLOAT  requires 8.0

I won't discuss whether NUMERIC or FLOAT *(fixed point, instead of floating point)* is more appropriate, when it comes to rounding errors, etc. I'll just let you google that if you need to, but FLOAT is so massively misused that there is a lot to read about the subject already out there.

You can try the following to see what happens...

CAST(SUM( AS NUMERIC(10,4)) * CAST(cp.price AS NUMERIC(10,4))

Is log(n!) = T(n·log(n))?

Remember that

log(n!) = log(1) + log(2) + ... + log(n-1) + log(n)

You can get the upper bound by

log(1) + log(2) + ... + log(n) <= log(n) + log(n) + ... + log(n)
                                = n*log(n)

And you can get the lower bound by doing a similar thing after throwing away the first half of the sum:

log(1) + ... + log(n/2) + ... + log(n) >= log(n/2) + ... + log(n) 
                                       = log(n/2) + log(n/2+1) + ... + log(n-1) + log(n)
                                       >= log(n/2) + ... + log(n/2)
                                        = n/2 * log(n/2) 

Disable scrolling in webview?

To Disable scroll use this

webView.setOnTouchListener(new View.OnTouchListener() {
    public boolean onTouch(View v, MotionEvent event) 
        return (event.getAction() == MotionEvent.ACTION_MOVE);

Adding the "Clear" Button to an iPhone UITextField

On Xcode 8 (8A218a):


textField.clearButtonMode = UITextField.ViewMode.whileEditing;

The "W" went from capital to non-cap "w".

Converting a column within pandas dataframe from int to string

Change data type of DataFrame column:

To int:

df.column_name = df.column_name.astype(np.int64)

To str:

df.column_name = df.column_name.astype(str)

How to execute an Oracle stored procedure via a database link

for me, this worked

exec utl_mail.send@myotherdb(
  sender => '[email protected]',recipients => '[email protected], 
  cc => null, subject => 'my subject', message => 'my message'

How do I count columns of a table

$cs = mysql_query("describe tbl_info");
$column_count = mysql_num_rows($cs);

Or just:

$column_count = mysql_num_rows(mysql_query("describe tbl_info"));

How do I create a batch file timer to execute / call another batch throughout the day

Below is a batch file that will wait for 1 minute, check the day, and then perform an action. It uses PING.EXE, but requires no files that aren't included with Windows.


ECHO Waiting for 1 minute...
  PING -n 60>nul
  IF %DATE:~0,3%==Mon CALL SomeOtherFile.cmd
  IF %DATE:~0,3%==Tue CALL SomeOtherFile.cmd
  IF %DATE:~0,3%==Wed CALL SomeOtherFile.cmd
  IF %DATE:~0,3%==Thu CALL WootSomeOtherFile.cmd
  IF %DATE:~0,3%==Fri CALL SomeOtherFile.cmd
  IF %DATE:~0,3%==Sat ECHO Saturday...nothing to do.
  IF %DATE:~0,3%==Sun ECHO Sunday...nothing to do.

It could be improved upon in many ways, but it might get you started.

Get table names using SELECT statement in MySQL

Take a look at the table TABLES in the database information_schema. It contains information about the tables in your other databases. But if you're on shared hosting, you probably don't have access to it.

Close iOS Keyboard by touching anywhere using Swift

Swift 3

override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {

How can I parse a string with a comma thousand separator to a number?

Remove anything that isn't a digit, decimal point, or minus sign (-):

var str = "2,299.00";
str = str.replace(/[^\d\.\-]/g, ""); // You might also include + if you want them to be able to type it
var num = parseFloat(str);

Updated fiddle

Note that it won't work for numbers in scientific notation. If you want it to, change the replace line to add e, E, and + to the list of acceptable characters:

str = str.replace(/[^\d\.\-eE+]/g, "");

how do you filter pandas dataframes by multiple columns

Start from pandas 0.13, this is the most efficient way.

df.query('Gender=="Male" & Year=="2014" ')

Highlight a word with jQuery

Is it possible to get this above example:

jQuery.fn.highlight = function (str, className)
    var regex = new RegExp(str, "g");

    return this.each(function ()
        this.innerHTML = this.innerHTML.replace(
            "<span class=\"" + className + "\">" + str + "</span>"

not to replace text inside html-tags like , this otherwise breakes the page.

How to iterate through two lists in parallel?

Here's how to do it with list comprehension:

a = (1, 2, 3)
b = (4, 5, 6)
[print('f:', i, '; b', j) for i, j in zip(a, b)]


f: 1 ; b 4
f: 2 ; b 5
f: 3 ; b 6

How to invert a grep expression

 grep "subscription" | grep -v "spec"  

Which is best data type for phone number in MySQL and what should Java type mapping for it be?

VARCHAR with probably 15-20 length would be sufficient and would be the best option for the database. Since you would probably require various hyphens and plus signs along with your phone numbers.

Android check null or empty string in Android

Incase all the answer given does not work, kindly try

String myString = null;

    //do something

Adding rows dynamically with jQuery

This will get you close, the add button has been removed out of the table so you might want to consider this...

<script type="text/javascript">
    $(document).ready(function() {
        $("#add").click(function() {
          $('#mytable tbody>tr:last').clone(true).insertAfter('#mytable tbody>tr:last');
          return false;

HTML markup looks like this

  <a  id="add">+</a></td>
  <table id="mytable" width="300" border="1" cellspacing="0" cellpadding="2">
    <tr class="person">
      <td><input type="text" name="name" id="name" /></td>

EDIT To empty a value of a textbox after insert..

    $('#mytable tbody>tr:last').clone(true).insertAfter('#mytable tbody>tr:last');
    $('#mytable tbody>tr:last #name').val('');
    return false;

EDIT2 Couldn't help myself, to reset all dropdown lists in the inserted TR you can do this

$("#mytable tbody>tr:last").each(function() {this.reset();});           

I will leave the rest to you!

Firebase Storage How to store and Retrieve images

I ended up storing the images in base64 format myself. I translate them from their base64 value when called back from firebase.

Check if space is in a string

word = ' '
while True:
    if ' ' in word:
        word = raw_input("Please enter a single word: ")
        print "Thanks"

This is more idiomatic python - comparison against True or False is not necessary - just use the value returned by the expression ' ' in word.

Also, you don't need to use pastebin for such a small snippet of code - just copy the code into your post and use the little 1s and 0s button to make your code look like code.

Scanner method to get a char

Java's Scanner class does not have a built in method to read from a Scanner character-by-character.

However, it should still be possible to fetch individual characters from the Scanner as follows:

Scanner sc:

char c = sc.findInLine(".").charAt(0);

And you could use it to fetch each character in your scanner like this:

    char c = sc.findInLine(".").charAt(0);
    System.out.println(c); //to print out every char in the scanner

The findInLine() method searches through your scanner and returns the first String that matches the regular expression you give it.

Setting up a git remote origin

You can include the branch to track when setting up remotes, to keep things working as you might expect:

git remote add --track master origin [email protected]:group/project.git   # git
git remote add --track master origin [email protected]:group/project.git   # git w/IP
git remote add --track master origin   # http
git remote add --track master origin # http w/IP
git remote add --track master origin /Volumes/Git/group/project/           # local
git remote add --track master origin G:/group/project/                     # local, Win

This keeps you from having to manually edit your git config or specify branch tracking manually.

IDENTITY_INSERT is set to OFF - How to turn it ON?

Add set off also


    INSERT INTO Genre(Id, Name, SortOrder)VALUES (12,'Moody Blues', 20) 


How can I check if a command exists in a shell script?

A function I have in an install script made for exactly this

function assertInstalled() {
    for var in "$@"; do
        if ! which $var &> /dev/null; then
            echo "Install $var!"
            exit 1

example call:

assertInstalled zsh vim wget python pip git cmake fc-cache

rawQuery(query, selectionArgs)

Maybe this can help you

Cursor c = db.rawQuery("query",null);
int id[] = new int[c.getCount()];
int i = 0;
if (c.getCount() > 0) 
    do {
        id[i] = c.getInt(c.getColumnIndex("field_name"));
    } while (c.moveToNext());

Controlling mouse with Python

Try with the PyAutoGUI module. It's multiplatform.

pip install pyautogui

And so:

import pyautogui, 100)

It also has other features:

import pyautogui
pyautogui.moveTo(100, 150)
pyautogui.moveRel(0, 10)  # move mouse 10 pixels down
pyautogui.dragTo(100, 150)
pyautogui.dragRel(0, 10)  # drag mouse 10 pixels down

This is much easier than going through all the win32con stuff.

CardView Corner Radius

You can use the standard MaterialCard included in the official Material Components library.

Use in your layout:


In your style use the shapeAppearanceOverlay attribute to customize the shape (the default corner radius is 4dp)

  <style name="MyCardView" parent="@style/Widget.MaterialComponents.CardView">
    <item name="shapeAppearanceOverlay">@style/ShapeAppearanceOverlay.MaterialCardView.Cut</item>

  <style name="ShapeAppearanceOverlay.MaterialCardView.Cut" parent="">
    <item name="cornerFamily">rounded</item>
    <item name="cornerSizeTopRight">8dp</item>
    <item name="cornerSizeTopLeft">8dp</item>
    <item name="cornerSizeBottomRight">0dp</item>
    <item name="cornerSizeBottomLeft">0dp</item>

You can also use:


It is the result:

enter image description here

MySQL stored procedure vs function, which would I use when?

The most general difference between procedures and functions is that they are invoked differently and for different purposes:

  1. A procedure does not return a value. Instead, it is invoked with a CALL statement to perform an operation such as modifying a table or processing retrieved records.
  2. A function is invoked within an expression and returns a single value directly to the caller to be used in the expression.
  3. You cannot invoke a function with a CALL statement, nor can you invoke a procedure in an expression.

Syntax for routine creation differs somewhat for procedures and functions:

  1. Procedure parameters can be defined as input-only, output-only, or both. This means that a procedure can pass values back to the caller by using output parameters. These values can be accessed in statements that follow the CALL statement. Functions have only input parameters. As a result, although both procedures and functions can have parameters, procedure parameter declaration differs from that for functions.
  2. Functions return value, so there must be a RETURNS clause in a function definition to indicate the data type of the return value. Also, there must be at least one RETURN statement within the function body to return a value to the caller. RETURNS and RETURN do not appear in procedure definitions.

    • To invoke a stored procedure, use the CALL statement. To invoke a stored function, refer to it in an expression. The function returns a value during expression evaluation.

    • A procedure is invoked using a CALL statement, and can only pass back values using output variables. A function can be called from inside a statement just like any other function (that is, by invoking the function's name), and can return a scalar value.

    • Specifying a parameter as IN, OUT, or INOUT is valid only for a PROCEDURE. For a FUNCTION, parameters are always regarded as IN parameters.

    If no keyword is given before a parameter name, it is an IN parameter by default. Parameters for stored functions are not preceded by IN, OUT, or INOUT. All function parameters are treated as IN parameters.

To define a stored procedure or function, use CREATE PROCEDURE or CREATE FUNCTION respectively:

CREATE PROCEDURE proc_name ([parameters])

CREATE FUNCTION func_name ([parameters])
 RETURNS data_type       // diffrent

A MySQL extension for stored procedure (not functions) is that a procedure can generate a result set, or even multiple result sets, which the caller processes the same way as the result of a SELECT statement. However, the contents of such result sets cannot be used directly in expression.

Stored routines (referring to both stored procedures and stored functions) are associated with a particular database, just like tables or views. When you drop a database, any stored routines in the database are also dropped.

Stored procedures and functions do not share the same namespace. It is possible to have a procedure and a function with the same name in a database.

In Stored procedures dynamic SQL can be used but not in functions or triggers.

SQL prepared statements (PREPARE, EXECUTE, DEALLOCATE PREPARE) can be used in stored procedures, but not stored functions or triggers. Thus, stored functions and triggers cannot use Dynamic SQL (where you construct statements as strings and then execute them). (Dynamic SQL in MySQL stored routines)

Some more interesting differences between FUNCTION and STORED PROCEDURE:

  1. (This point is copied from a blogpost.) Stored procedure is precompiled execution plan where as functions are not. Function Parsed and compiled at runtime. Stored procedures, Stored as a pseudo-code in database i.e. compiled form.

  2. (I'm not sure for this point.)
    Stored procedure has the security and reduces the network traffic and also we can call stored procedure in any no. of applications at a time. reference

  3. Functions are normally used for computations where as procedures are normally used for executing business logic.

  4. Functions Cannot affect the state of database (Statements that do explicit or implicit commit or rollback are disallowed in function) Whereas Stored procedures Can affect the state of database using commit etc.
    refrence: J.1. Restrictions on Stored Routines and Triggers

  5. Functions can't use FLUSH statements whereas Stored procedures can do.

  6. Stored functions cannot be recursive Whereas Stored procedures can be. Note: Recursive stored procedures are disabled by default, but can be enabled on the server by setting the max_sp_recursion_depth server system variable to a nonzero value. See Section 5.2.3, “System Variables”, for more information.

  7. Within a stored function or trigger, it is not permitted to modify a table that is already being used (for reading or writing) by the statement that invoked the function or trigger. Good Example: How to Update same table on deletion in MYSQL?

Note: that although some restrictions normally apply to stored functions and triggers but not to stored procedures, those restrictions do apply to stored procedures if they are invoked from within a stored function or trigger. For example, although you can use FLUSH in a stored procedure, such a stored procedure cannot be called from a stored function or trigger.

How to add a line break in an Android TextView?

As I know in the previous version of android studio uses separate lines " \n " code. But new one (4.1.2) uses "<br/" to separate lines. For example - Old one:

<string name="string_name">Sample text 1 \n Sample text 2 </string>

New one:

<string name="string_name">Sample text 1 <br/> Sample text 2 </string>

How to add a custom CA Root certificate to the CA Store used by pip in Windows?

Alternative solution on Windows is to install python-certifi-win32 that will allow Python to use Windows Certificate Store.

pip install python-certifi-win32

How to show and update echo on same line

The rest of answers are pretty good, but just wanted to add some extra information in case someone comes here looking for a solution to replace/update a multiline echo.

So I would like to share an example with you all. The following script was tried on a CentOS system and uses "timedatectl" command which basically prints some detailed time information of your system.

I decided to use that command as its output contains multiple lines and works perfectly for the example below:

while true; do
  COMMAND=$(timedatectl) #Save command result in a var.
  echo "$COMMAND" #Print command result, including new lines.

  sleep 3 #Keep above's output on screen during 3 seconds before clearing it

  #Following code clears previously printed lines
  LINES=$(echo "$COMMAND" | wc -l) #Calculate number of lines for the output previously printed
  for (( i=1; i <= $(($LINES)); i++ ));do #For each line printed as a result of "timedatectl"
    tput cuu1 #Move cursor up by one line
    tput el #Clear the line


The above will print the result of "timedatectl" forever and will replace the previous echo with updated results.

I have to mention that this code is only an example, but maybe not the best solution for you depending on your needs. A similar command that would do almost the same (at least visually) is "watch -n 3 timedatectl".

But that's a different story. :)

Hope that helps!

Detecting the character encoding of an HTTP POST request

the default encoding of a HTTP POST is ISO-8859-1.

else you have to look at the Content-Type header that will then look like

Content-Type: application/x-www-form-urlencoded ; charset=UTF-8

You can maybe declare your form with

<form enctype="application/x-www-form-urlencoded;charset=UTF-8">


<form accept-charset="UTF-8">

to force the encoding.

Some references :

How do I install a color theme for IntelliJ IDEA 7.0.x

Step 1: Do File -> Import Settings... and select the settings jar file

Step 2: Go to Settings -> Editor -> Colors and Fonts to choose the theme you just installed.

Selecting one row from MySQL using mysql_* API

$result = mysql_query("SELECT option_value FROM wp_10_options WHERE option_name='homepage'");
$row = mysql_fetch_assoc($result);
echo $row['option_value'];

How to detect control+click in Javascript from an onclick div attribute?

When there is a mouse click ctrlKey is event attribute which can be accessed as e.ctrlKey. Look down for example

    //if ctrl key is pressed
    // if ctrl key is not pressed


Is java.sql.Timestamp timezone specific?

For Mysql, we have a limitation. In the driver Mysql doc, we have :

The following are some known issues and limitations for MySQL Connector/J: When Connector/J retrieves timestamps for a daylight saving time (DST) switch day using the getTimeStamp() method on the result set, some of the returned values might be wrong. The errors can be avoided by using the following connection options when connecting to a database:


So, when we do not use this parameters and we call setTimestamp or getTimestamp with calendar or without calendar, we have the timestamp in the jvm timezone.

Example :

The jvm timezone is GMT+2. In the database, we have a timestamp : 1461100256 = 19/04/16 21:10:56,000000000 GMT

Properties props = new Properties();
props.setProperty("user", "root");
props.setProperty("password", "");
props.setProperty("useTimezone", "true");
props.setProperty("useLegacyDatetimeCode", "false");
props.setProperty("serverTimezone", "UTC");
Connection con = DriverManager.getConnection(conString, props);
Calendar nowGMT = Calendar.getInstance(TimeZone.getTimeZone("GMT"));
Calendar nowGMTPlus4 = Calendar.getInstance(TimeZone.getTimeZone("GMT+4"));
rs.getTimestamp("timestampColumn");//Oracle driver convert date to jvm timezone and Mysql convert date to GMT (specified in the parameter)
rs.getTimestamp("timestampColumn", nowGMT);//convert date to GMT 
rs.getTimestamp("timestampColumn", nowGMTPlus4);//convert date to GMT+4 timezone

The first method returns : 1461100256000 = 19/04/2016 - 21:10:56 GMT

The second method returns : 1461100256000 = 19/04/2016 - 21:10:56 GMT

The third method returns : 1461085856000 = 19/04/2016 - 17:10:56 GMT

Instead of Oracle, when we use the same calls, we have :

The first method returns : 1461093056000 = 19/04/2016 - 19:10:56 GMT

The second method returns : 1461100256000 = 19/04/2016 - 21:10:56 GMT

The third method returns : 1461085856000 = 19/04/2016 - 17:10:56 GMT

NB : It is not necessary to specify the parameters for Oracle.

HTML5 form required attribute. Set custom validation message?

I have a simpler vanilla js only solution:

For checkboxes:

document.getElementById("id").oninvalid = function () {
    this.setCustomValidity(this.checked ? '' : 'My message');

For inputs:

document.getElementById("id").oninvalid = function () {
    this.setCustomValidity(this.value ? '' : 'My message');

Find and Replace Inside a Text File from a Bash Command

You can use rpl command. For example you want to change domain name in whole php project.

rpl -ivRpd -x'.php' '' '' ./path_to_your_project_folder/  

This is not clear bash of cause, but it's a very quick and usefull. :)

What is the theoretical maximum number of open TCP connections that a modern Linux box can have

If you used a raw socket (SOCK_RAW) and re-implemented TCP in userland, I think the answer is limited in this case only by the number of (local address, source port, destination address, destination port) tuples (~2^64 per local address).

It would of course take a lot of memory to keep the state of all those connections, and I think you would have to set up some iptables rules to keep the kernel TCP stack from getting upset &/or responding on your behalf.

How to get EditText value and display it on screen through TextView?

EditText ein=(EditText)findViewById(;
TextView t=new TextView(this);
t.setText("Your Text is="+ein.getText());

Is a GUID unique 100% of the time?

Is a GUID unique 100% of the time?

Not guaranteed, since there are several ways of generating one. However, you can try to calculate the chance of creating two GUIDs that are identical and you get the idea: a GUID has 128 bits, hence, there are 2128 distinct GUIDs – much more than there are stars in the known universe. Read the wikipedia article for more details.

Cannot find module cv2 when using OpenCV

Another way I got opencv to install and work was inside visual studio 2017 community. Visual studio has a nice python environment with debugging.
So from the vs python env window I searched and added opencv. Just thought I would share because I like to try things different ways and on different computers.

VisualStudio2017 python environments with opencv

How can I read large text files in Python, line by line, without loading it into memory?

I demonstrated a parallel byte level random access approach here in this other question:

Getting number of lines in a text file without readlines

Some of the answers already provided are nice and concise. I like some of them. But it really depends what you want to do with the data that's in the file. In my case I just wanted to count lines, as fast as possible on big text files. My code can be modified to do other things too of course, like any code.

SQL Server 2005 Using DateAdd to add a day to a date

DECLARE @MyDate datetime

-- ... set your datetime's initial value ...'

DATEADD(d, 1, @MyDate)

Google Chrome form autofill and its yellow background

I use this,

input:-webkit-autofill { -webkit-box-shadow: 0 0 0px 1000px white inset !important; }
input:focus:-webkit-autofill { -webkit-box-shadow: 0 0 0px 1000px white inset !important; }
/* You can use color:#color to change the color */

How to get current CPU and RAM usage in Python?

The psutil library gives you information about CPU, RAM, etc., on a variety of platforms:

psutil is a module providing an interface for retrieving information on running processes and system utilization (CPU, memory) in a portable way by using Python, implementing many functionalities offered by tools like ps, top and Windows task manager.

It currently supports Linux, Windows, OSX, Sun Solaris, FreeBSD, OpenBSD and NetBSD, both 32-bit and 64-bit architectures, with Python versions from 2.6 to 3.5 (users of Python 2.4 and 2.5 may use 2.1.3 version).

Some examples:

#!/usr/bin/env python
import psutil
# gives a single float value
# gives an object with many fields
# you can convert that object to a dictionary 
# you can have the percentage of used RAM
# you can calculate percentage of available memory
psutil.virtual_memory().available * 100 / psutil.virtual_memory().total

Here's other documentation that provides more concepts and interest concepts:

Where value in column containing comma delimited values

            LOCATE(',DOG,', CONCAT(',',COLUMN,','))>0 OR
            LOCATE(',CAT,', CONCAT(',',COLUMN,','))>0

unary operator expected in shell script when comparing null value with string

Why all people want to use '==' instead of simple '=' ? It is bad habit! It used only in [[ ]] expression. And in (( )) too. But you may use just = too! It work well in any case. If you use numbers, not strings use not parcing to strings and then compare like strings but compare numbers. like that

let -i i=5 # garantee that i is nubmber
test $i -eq 5 && echo "$i is equal 5" || echo "$i not equal 5"

It's match better and quicker. I'm expert in C/C++, Java, JavaScript. But if I use bash i never use '==' instead '='. Why you do so?

ImageButton in Android


works automatically.


was what I used with all the problems of resizing the image the the width and height of the button...

Android Studio marks R in red with error message "cannot resolve symbol R", but build succeeds

The better way to resolve this problem is to restart your Android Studio. If you don't want to do a restart, then click on Build -> Clean Project.

How to solve SQL Server Error 1222 i.e Unlock a SQL Server table

I had these SQL behavior settings enabled on options query execution: ANSI SET IMPLICIT_TRANSACTIONS checked. On execution of your query e.g create, alter table or stored procedure, you have to COMMIT it.

Just type COMMIT and execute it F5

Deserialize a json string to an object in python

You can specialize an encoder for object creation:

import json
class ComplexEncoder(json.JSONEncoder):
    def default(self, obj):
        if isinstance(obj, complex):
            return {"real": obj.real,
            "imag": obj.imag,
            "__class__": "complex"}
        return json.JSONEncoder.default(self, obj)

print json.dumps(2 + 1j, cls=ComplexEncoder)

Using LINQ to group a list of objects

The desired result can be obtained using IGrouping, which represents a collection of objects that have a common key in this case a GroupID

 var newCustomerList = CustomerList.GroupBy(u => u.GroupID)
                                                  .Select(group => new { GroupID = group.Key, Customers = group.ToList() })

How to Increase Import Size Limit in phpMyAdmin

Change these values in php.ini

post_max_size = 750M 
upload_max_filesize = 750M 
max_execution_time = 5000 
max_input_time = 5000 
memory_limit = 1000M 

Then restart Wamp for the changes to take effect. It will take some time. If you get following error:

Script timeout passed if you want to finish import please resubmit same zip file and import will resume.

Then update the phpMyAdmin configuration, at phpMyAdmin\libraries\config.default.php

 * maximum execution time in seconds (0 for no limit)
 * @global integer $cfg['ExecTimeLimit']
$cfg['ExecTimeLimit'] = 0;

Pythonically add header to a csv file

This worked for me.

header = ['row1', 'row2', 'row3']
some_list = [1, 2, 3]
with open('test.csv', 'wt', newline ='') as file:
    writer = csv.writer(file, delimiter=',')
    writer.writerow(i for i in header)
    for j in some_list:

Could not find the main class, program will exit

I had this problem when I "upgraded" to Windows 7, which is 64-bit. My go to Java JRE is a 64-bit JVM. I had a 32-bit JRE on my machine for my browser, so I set up a system variable:

JRE32=C:\Program Files\Java\jre7

When I run:

"%JRE32\bin\java" -version

I get:

java version "1.7.0_51"
Java(TM) SE Runtime Environment (build 1.7.0_51-b13)
Java HotSpot(TM) Client VM (build 24.51-b03, mixed mode, sharing)

Which is a 32-bit JVM. It would say "Java HotSpot(TM) 64-Bit" otherwise.

I edited the "squirrel-sql.bat" file, REMarking out line 4 and adding line 5 as follows:

(4) rem set "IZPACK_JAVA=%JAVA_HOME%"
(5) set IZPACK_JAVA=%JRE32%

And now everything works, fine and dandy.

How do I return JSON without using a template in Django?

I think the issue has gotten confused regarding what you want. I imagine you're not actually trying to put the HTML in the JSON response, but rather want to alternatively return either HTML or JSON.

First, you need to understand the core difference between the two. HTML is a presentational format. It deals more with how to display data than the data itself. JSON is the opposite. It's pure data -- basically a JavaScript representation of some Python (in this case) dataset you have. It serves as merely an interchange layer, allowing you to move data from one area of your app (the view) to another area of your app (your JavaScript) which normally don't have access to each other.

With that in mind, you don't "render" JSON, and there's no templates involved. You merely convert whatever data is in play (most likely pretty much what you're passing as the context to your template) to JSON. Which can be done via either Django's JSON library (simplejson), if it's freeform data, or its serialization framework, if it's a queryset.


from django.utils import simplejson

some_data_to_dump = {
   'some_var_1': 'foo',
   'some_var_2': 'bar',

data = simplejson.dumps(some_data_to_dump)


from django.core import serializers

foos = Foo.objects.all()

data = serializers.serialize('json', foos)

Either way, you then pass that data into the response:

return HttpResponse(data, content_type='application/json')

[Edit] In Django 1.6 and earlier, the code to return response was

return HttpResponse(data, mimetype='application/json')

[EDIT]: simplejson was remove from django, you can use:

import json

json.dumps({"foo": "bar"})

Or you can use the django.core.serializers as described above.

SQL statement to select all rows from previous day

This should do it:


If two cells match, return value from third

I think what you want is something like:


I should mention that MATCH checks the position at which the value can be found within A:A (given the 0, or FALSE, parameter, it looks only for an exact match and given its nature, only the first instance found) then INDEX returns the value at that position within B:B.

System.BadImageFormatException: Could not load file or assembly (from installutil.exe)

My issue was different. This occurred after an unexpected shutdown of my windows 7 machine. I performed a clean solution and it ran as expected.

Distribution certificate / private key not installed

i tried all mentioned solutions available on the internet but no solution working on my Mac, then i created a provisioning profile manually on apple developer website from certificates and identifiers. By importing that file manually app successfully uploaded on appStore follow below steps

On Developer website

1-go to this link

2- In profile Section create new profile by using app bundle identifier

3-Download it and save it an where

On Xcode

1-Go to Signing and certificates

2-Disable automatically manage signing

3- Select provisioning profile in its section

4- Archive the app

5-Click Distribute App ->ApStore connect ->Upload->Next-> Then Select Profile from XXXX-app section when it download it show inside this section and now upload it

github changes not staged for commit

I tried everything suggested on whole Stackoverflow. Nothing including -a or -am or anything helped.

If you are the same, do this.

So, the problem is, git thinks some of your subdirectory is sub-project in your root-project. At least, in my case it wasn't like that. It was just regular sub-directory. Not individual project.

Move that regular sub-directory which is not being pushed at some temporary location.

Remove the hidden .git folder from that directory.

cd to the root directory.

git init again.

git add . again.

git commit -m "removed notPushableDirectory temporarily"

git push -f origin master

We will have to force it as the git will see the conflict between remote git and your local structure. Remember, we created this conflict. So, don't worry about forcing it.

Now, it will push that sub-directory as sub-directory and not as sub-module or sub-project inside your root-project.