Question

Question1:

MySQL table

id | array
1 | 1,2,3
2 | 2
3 | 2,3
4 | 4,5,6

$_GET['id'] = 2;
$a = mysql_query("SELECT * FROM `table` WHERE `array` ??? '$_GET[id]'");

In this step, I want to run through the entire array and see if it matches with the $_GET[‘id’], so it should output:

ids: 1,2,3

Question2:

MySQL table

id | array
1 | 4,5,6
2 | 3,4,7

$_GET['id'] = 4;
$a = mysql_query("SELECT * FROM `table` WHERE `array` ??? '$_GET[id]'");

In this step, I only want to match against the first element in the array, so it should output:

id: 4

I can only think of using PHP to do this, but I’d rather do all that just within the MySQL query, if that is even possible.

$a = mysql_query("SELECT * FROM `table`");
while($b = mysql_fetch_assoc($a))
{
    $elements = explode(',', $b['array']);
    foreach($elements as $element)
    {
        if($element == $_GET['id'])
        {
            echo $b['id'].'<br />';
        }
    }
}

or

$a = mysql_query("SELECT * FROM `table`");
while($b = mysql_fetch_assoc($a))
{
    $array = $b['array'];

    if(in_array($_GET['id'], $array))
    {
        echo $b['id'].'<br />';
    }
}

that would look just awful.

Answer 1

Your data structure in the DB is not optimal for querying the way you want it.

For the first question:

mysql_query("SELECT * FROM table WHERE array LIKE '%,$_GET[id],%' OR array LIKE '$_GET[id],%' OR array LIKE '%,$_GET[id]' OR array = '$_GET[id]'");

For the second:

mysql_query("SELECT id, SUBSTR(array, 1, POSITION(',' IN array) - 1) AS array FROM table WHERE array LIKE '$_GET[id],%' OR array = '$_GET[id]'");

As you can see, these queries aren’t pretty, but they’ll do what you want.