json encode is returning NULL

Question

For some reason the item  description  returns NULL with the following code    lt  php include  db php      result   mysql query  SELECT   FROM  staff  ORDER BY  id  DESC LIMIT 2   or die mysql error      rows   array    while  row   mysql fetch assoc  result         rows      row     echo json encode  rows     gt    Here is the schema for my database   CREATE TABLE  staff       id  int 11  NOT NULL AUTO INCREMENT     name  longtext COLLATE utf8 unicode ci     description  longtext COLLATE utf8 unicode ci     icon  longtext COLLATE utf8 unicode ci     date  longtext COLLATE utf8 unicode ci     company  longtext COLLATE utf8 unicode ci     companyurl  longtext COLLATE utf8 unicode ci     appurl  longtext COLLATE utf8 unicode ci    PRIMARY KEY   id     ENGINE MyISAM AUTO INCREMENT 5 DEFAULT CHARSET utf8 COLLATE utf8 unicode ci   Here is what is echoed out on the page      id   4   name   Noter 2   description  null  icon   http     images apple com  webapps  productivity  images  noter2 20091223182720-thumb jpg   date   1262032317   company   dBelement  LLC   companyurl   http     dbelement com     appurl   http     noter2 dbelement com     id   3   name   Noter 2   description  null  icon   http     images apple com  webapps  productivity  images  noter2 20091223182720-thumb jpg   date   1262032317   company   dBelement  LLC   companyurl   http     dbelement com     appurl   http     noter2 dbelement com      Any ideas

User · Answer

I had the same problem and the solution was to use my own function instead of json encode    echo        implode         row

User · Answer

few day ago I have the SAME problem with 1 table    Firstly try    echo json encode  rows   echo json last error        returns 5     If last line returns 5  problem is with your data  I know  your tables are in UTF-8  but not entered data  For example the input was in txt file  but created on Win machine with stupid encoding  in my case Win-1250   CP1250  and this data has been entered into the DB   Solution  Look for new data  excel  web page   edit source txt file via PSPad  or whatever else   change encoding to UTF-8  delete all rows and now put data from original  Save  Enter into DB    You can also only change encoding to utf-8 and then change all rows manually  give cols with special chars - desc        Good for slaves

User · Answer

The PHP net recommended way of setting the charset is now this   mysqli set charset  utf8

User · Answer

If you have at least PHP 5 5  you can use json last error msg    which will return a string describing the problem   If you don t have 5 5  but are on above 5 3  you can use json last error   to see what the problem is   It will return an integer  that you can use to identify the problem in the function s documentation  Currently  2012 01 19   the identifiers are   0   JSON ERROR NONE 1   JSON ERROR DEPTH 2   JSON ERROR STATE MISMATCH 3   JSON ERROR CTRL CHAR 4   JSON ERROR SYNTAX 5   JSON ERROR UTF8   These can change in future versions  so it s better to consult the manual   If you are below 5 3  you are out of luck  there is no way to ask what the error was

User · Answer

You should pass utf8 encoded string in json encode  You can use utf8 encode and array map   function like below    lt  php      encoded rows   array map  utf8 encode    rows       echo json encode  encoded rows     gt

User · Answer

For me  an issue where json encode would return null encoding of an entity was because my jsonSerialize implementation fetched entire objects for related entities  I solved the issue by making sure that I fetched the ID of the related associated entity and called - toArray   when there were more than one entity associated with the object to be json serialized  Note  I m speaking about cases where one implements JsonSerializable on entities

User · Answer

ntd s anwser didn t solve my problem  For those in same situation  here is how I finally handled this error  Just utf8 encode each of your results   while  row   mysql fetch assoc  result         rows     array map  utf8 encode    row       Hope it helps

User · Answer

For anyone using PDO  the solution is similar to ntd s answer  From the PHP PDO    construct page  as a comment from the user Kiipa at live dot com   To get UTF-8 charset you can specify that in the DSN   link   new PDO  quot mysql host localhost dbname DB charset UTF8 quot

User · Answer

I bet you are retrieving data in non-utf8 encoding  try to put mysql query  SET CHARACTER SET utf8   before your SELECT query

User · Answer

AHHH    This looks so wrong it hurts my head  Try something more like this      lt  php include  db php      result   mysql query  SELECT  id    name    description    icon  FROM  staff  ORDER BY  id  DESC LIMIT 20   or die mysql error      rows   array    while  row   mysql fetch assoc  result         rows      row     echo json encode  rows     gt     When iterating over mysql num rows you should use  lt  not  lt    You should also cache this value  save it to a variable  instead of having it re-count every loop  Who knows what it s doing under the hood     might be efficient  I m not really sure  You don t need to copy out each value explicitly like that    you re just making this harder on yourself  If the query is returning more values than you ve listed there  list only the ones you want in your SQL  mysql fetch array returns the values both by key and by int  You not using the indices  so don t fetch em    If this really is a problem with json encode  then might I suggest replacing the body of the loop with something like   rows     array map  htmlentities   row     Perhpas there are some special chars in there that are mucking things up

[php] json_encode is returning NULL?

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