Question

Is it possible to first SELECT from DB and then if something is true INSERT into db within the same query?

Here is how I do right now:

$sql = mysql_query("SELECT * FROM ".$prefix."_active_users WHERE userid = $playerid AND DATE(timestamp) = '$sel_tag'");
$row = mysql_fetch_assoc($sql);

if(!$row){
     mysql_query("INSERT INTO ".$prefix."_active_users (userid,timestamp) VALUES ($playerid,'$now')");
}

Hoping for help and thanks 😉

Answer 1

As I read the question, you want to INSERT if no row exists.

So, in one query…

mysql_query("

   INSERT INTO ".$prefix."_active_users (userid,timestamp)
   SELECT $playerid, '$now'
   FROM dual
   WHERE NOT EXISTS (SELECT * FROM ".$prefix."_active_users
             WHERE userid = $playerid AND   DATE(timestamp) = '$sel_tag')
    ");

This is different to the other answers then INSERT.. SELECT