Question

I’m storing JSON data in a MySQL table using the code below. It works fine if the JSON is short but breaks for longer text. The “field_json” is a LONGTEXT.

$sql = sprintf("UPDATE mytable 
    SET field_json = '$json_string'
    WHERE id = $userid");
$result = mysql_query($sql);

The error I’m getting is:

Invalid query: 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 ‘G
‘”,”username”:”C0WB0Y”,”lastName”:””,”id”:31874363},{“pathToPhoto”:”22960/phot’
at line 2

Answer 1

Use place holders otherwise you are susceptible to SQL injection: http://php.net/manual/en/mysqli.quickstart.prepared-statements.php

Otherwise, here’s a quick fix: http://php.net/manual/en/function.mysql-real-escape-string.php

$sql = sprintf(
        "UPDATE mytable SET field_json = '%s' WHERE id = '%s'",
        mysql_real_escape_string($json_string),
        mysql_real_escape_string($userid)
);
$result = mysql_query($sql);

EDIT

Please use PDO ( http://www.php.net/manual/en/book.pdo.php ). The mysql extension has been deprecated as of 5.5