How to retrieve data from sqlite database in android and display it in TextView

Question

I am learning Android  I have a problem and I can t solve it  I want to retrieve data from an existing database and display it in a TextView after click button    My code DataBaseHelper looks like this   public class DataBaseHelper extends SQLiteOpenHelper                  The Android s default system path of your application database                  private static String DB PATH     data data in ekonomia android databases                     private static String DB NAME    cytaty                    private SQLiteDatabase myDataBase                    private final Context myContext                          Constructor       Takes and keeps a reference of the passed context in order to access to the application assets and resources         param context                public DataBaseHelper Context context                        super context  DB NAME  null  1                   this myContext   context                                 Creates a empty database on the system and rewrites it with your own database                   public void createDataBase   throws IOException                      boolean dbExist   checkDataBase                  if dbExist                             do nothing - database already exist                     else                              By calling this method and empty database will be created into the default system path                                  of your application so we are gonna be able to overwrite that database with our database                           this getReadableDatabase                                 try                                                       copyDataBase                                       catch  IOException e                                                                throw new Error  Error copying database                                                                                                   Check if the database already exist to avoid re-copying the file each time you open the application         return true if it exists  false if it doesn t                private boolean checkDataBase               SQLiteDatabase checkDB   null            try                           String myPath   DB PATH   DB NAME                    checkDB   SQLiteDatabase openDatabase myPath  null  SQLiteDatabase OPEN READONLY                  catch  SQLiteException e                                     database does t exist yet                                   if checkDB    null                           checkDB close                                 return checkDB    null   true   false                               Copies your database from your local assets-folder to the just created empty database in the       system folder  from where it can be accessed and handled        This is done by transfering bytestream                   private void copyDataBase   throws IOException                        Open your local db as the input stream                 InputStream myInput   myContext getAssets   open DB NAME                    Path to the just created empty db                 String outFileName   DB PATH   DB NAME                     Open the empty db as the output stream                 OutputStream myOutput   new FileOutputStream outFileName                   transfer bytes from the inputfile to the outputfile                byte   buffer   new byte 1024                int length               while   length   myInput read buffer   gt 0                                   myOutput write buffer  0  length                                        Close the streams              myOutput flush                   myOutput close                   myInput close                            public void openDataBase   throws SQLException                     Open the database                String myPath   DB PATH   DB NAME                myDataBase   SQLiteDatabase openDatabase myPath  null  SQLiteDatabase OPEN READONLY                            Override            public synchronized void close                             if myDataBase    null                        myDataBase close                     super close                    Override        public void onCreate SQLiteDatabase db                     Override        public void onUpgrade SQLiteDatabase db  int oldVersion  int newVersion                       Add your public helper methods to access and get content from the database                You could return cursors by doing  return myDataBase query        so it d be easy               to you to create adapters for your views            Cytaty java looks like this   package in ekonomia android   import android app Activity  import android os Bundle  import android view View  import android widget Button    public class cytaty extends Activity          Override     protected void onCreate Bundle savedInstanceState               TODO Auto-generated method stub         super onCreate savedInstanceState           setContentView R layout galeria             Button bLosuj    Button  findViewById R id button1           bLosuj setOnClickListener new View OnClickListener                  public void onClick View v                       TODO Auto-generated method stub                                                 I did as above and Eclipse gives me errors    Database name  cytaty name of table  cytaty columns   id  autor  cytat    My code is    public void getData         public String   getAppCategorydetail             String Table Name  cytaty            String selectQuery    SELECT    FROM     Table Name                SQLiteDatabase db   this getReadableDatabase            Cursor cursor   db rawQuery selectQuery  null                    String   data   null          if  cursor moveToFirst                  do                     get  the  data into array or class variable               while  cursor moveToNext                       db close            return data             And    Button bLosuj    Button  findViewById R id button1       bLosuj setOnClickListener new View OnClickListener              public void onClick View v                   TODO Auto-generated method stub             DataBaseHelper myDataBaseHelper   new DataBaseHelper cytaty this                  myDataBaseHelper openDataBase                    String text  myDataBaseHelper getData     this is the method to query                myDataBaseHelper close                    set text to your TextView              TextView tekst    TextView  findViewById R id editText1               tekst setText text                                 What am I doing wrong   I want retrieve data from database and show in TextView after click button   Your help would be appreciated

User · Answer

First cast your Edit text like this    TextView tekst    TextView  findViewById R id editText1   tekst setText text     And after that close the DB not befor this line      myDataBaseHelper close

User · Answer

You are using getData   method as void   You can not return values from void

User · Answer

on button click  first open the database  fetch the data and close the data base like this  public class cytaty extends Activity         Override     protected void onCreate Bundle savedInstanceState            super onCreate savedInstanceState           setContentView R layout galeria            Button bLosuj    Button  findViewById R id button1           bLosuj setOnClickListener new View OnClickListener              public void onClick View v                myDatabaseHelper   new DatabaseHelper cytaty this               myDatabaseHelper openDataBase                 String text   myDatabaseHelper getYourData      this is the method to query              myDatabaseHelper close                    set text to your TextView                                     and your getYourData   in database class would be like this  public String   getAppCategoryDetail          final String TABLE NAME    name of table        String selectQuery    SELECT    FROM     TABLE NAME      SQLiteDatabase db    this getReadableDatabase        Cursor cursor        db rawQuery selectQuery  null       String   data        null       if  cursor moveToFirst              do                 get the data into array  or class variable           while  cursor moveToNext               cursor close        return data

User · Answer

You may use this following code actually it is rough but plz check it out  db   openOrCreateDatabase  sms db   SQLiteDatabase CREATE IF NECESSARY  null   Cursor cc   db rawQuery  SELECT   FROM datatable   null   final ArrayList lt String gt  row1   new ArrayList lt String gt     final ArrayList lt String gt  row2   new ArrayList lt String gt      if cc  null        cc moveToFirst           startManagingCursor cc       for  int i 0  i lt cc getCount    i           String number    cc getString 0       String message   cc getString 1       row1 add number       row2 add message        final EditText et3    EditText  findViewById R id editText3       final EditText et4    EditText  findViewById R id editText4       Button bt1    Button  findViewById R id button1       bt1 setOnClickListener new OnClickListener               Override         public void onClick View v                   TODO Auto-generated method stub              switch  v getId                      case R id button1                      et3 setText row1 get count                        et4 setText row2 get count                        count                        break                  default                      break                                    cc moveToNext

User · Answer

TextView tekst    TextView  findViewById R id editText1      You cannot cast EditText to TextView

[android] How to retrieve data from sqlite database in android and display it in TextView

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