android - How do I setup a 2d Json Array using php for a sql server? -


i have following php code, storing last row of data query returns. how can store data in json array can access through android , populate list view?

<?php  header('content-type: application/json ');     $dbhost = 'localhost';     $dbuser = 'root';     $dbpass = 'pass';     $conn = mysql_connect($dbhost, $dbuser, $dbpass);     if(! $conn ) {       die('could not connect: ' . mysql_error());    }     $sql = 'select * tb_name';    mysql_select_db('db_name');    $retval = mysql_query( $sql, $conn );     if(! $retval ) {       die('could not data: ' . mysql_error());    }     while($rows=mysql_fetch_assoc($retval)){         $json['cola'] = $rows['cola'];         $json['colb'] = $rows['colb']; }    echo json_encode($json);    mysql_close($conn); ?> 

the following code produces following json array data last row:

{   "cola": "contents of a",   "colb": "contents of b" } 

how can store rows returns in way keys separate so:

{     {       "cola": "contents of a",       "colb": "contents of b"     },     {       "cola": "contents of a",       "colb": "contents of b"     },     {       "cola": "contents of a",       "colb": "contents of b"     } } 

i know syntax might not right json file, thats want accomplish, missing?

you override data in while-loop. can this:

while($rows=mysql_fetch_assoc($retval)){         $row['cola'] = $rows['cola'];     $row['colb'] = $rows['colb'];     $json[] = $row; }