Question

I have this query that checks if a movement exists and supposed to return true or false. This query

function movement_performed_today($class_id, $client_id){
$class_id = (int)$class_id;
$client_id = (int)$client_id;



$query = mysql_query("SELECT COUNT(`movement`) FROM `completed_movements` WHERE `class_id` = '$class_id' AND `client_id` = '$client_id' AND `date` = CURDATE()");

$movement_performed = mysql_fetch_assoc($query);

$return = (mysql_result($movement_performed, 0) == 1) ? true : false;   
    var_dump ($return);
}

Returns:

bool(false) 
bool(false)

If I replace this code:

$return = result(mysql_result($movement_performed, 0) == 1) ? true : false; 
    var_dump ($return);

With this:

print_r ($movement_perfomed);

Returns:

Array ( [COUNT(`movement`)] => 2 ) 
Array ( [COUNT(`movement`)] => 3 )

Am I completely wrong to think since these numbers are anything other than zero it should return true?

Answer 1

To answer your question:

mysql_result returns FALSE on error. You are passing the array from mysql_fetch_assoc instead of the mysql resource as required by mysql_result‘s function signature:

string mysql_result ( resource $result , int $row [, mixed $field = 0 ] )

Thus it returns FALSE because it has an error.

---

A better way:

// Change
$movement_performed = mysql_fetch_assoc($query);
$return = result(mysql_result($movement_performed, 0) == 1) ? true : false;

// to
$movement_performed = mysql_fetch_row($query);
return $movement_performed[0] > 0;

This grabs the result of the count statement and does a > 0 check on it. The > 0 check is not really needed but helps show intent rather than relying on on truthy values.

---

Side note: the mysql_* functions have been deprecated. You should migrate your code to use MySQLi or PDO. You are unfortunately using the fact that many mysql_* functions do not need the mysql resource. Migrating your code will be a pain because you have to change a bunch of functions or declare global variables. I recommend the former option but it will take a lot of effort to fix.