Question

I’m posting a JSONArray.toString() to a php file. The JSONArray contains a set of id values. I want to make a mysql query that only returns rows that have an id contained in the jsonarray. My method below isn’t working. Is there another way?

$jsonarray= $_POST["ids"];
$query = mysql_query("SELECT * FROM table WHERE id IN $jsonarray")or die(mysql_error());

Answer 1

It’d help if we had an example of the JSON array, however, you should decode the JSON array into a comma separated list to use with IN.

$jsonarray = $_POST["ids"];
$ids = implode(",", json_decode($jsonarray,true));

$query = mysql_query("SELECT * FROM table WHERE id IN ($ids)")or die(mysql_error());

Also, you should be using mysqli or PDO_MySQL for new development:

It is recommended to use either the mysqli or PDO_MySQL extensions. It
is not recommended to use the old mysql extension for new development.
A detailed feature comparison matrix is provided below. The overall
performance of all three extensions is considered to be about the
same. Although the performance of the extension contributes only a
fraction of the total run time of a PHP web request. Often, the impact
is as low as 0.1%.

Related Reading:

• http://php.net/manual/en/mysqlinfo.api.choosing.php
• http://www.php.net/manual/en/mysqlinfo.library.choosing.php