Question

I have a php comma separated string
$string = (x,y,z)

I have a column in mysql that has items (y,z)

I want to make an array of the items that are in the string but not in the table column…

 $cid = "'" . str_replace(",", "','", $cid) . "'";

    $query = mysql_query("SELECT save_key FROM saved WHERE save_key IN ($cid)");

    while ($result = mysql_fetch_assoc($query)){
        $array[] = $result['save_key'];
    }

    $cid_array = explode(',',$cid);

    $dif = array_diff($cid_array, $array);

    print_r($dif);

Output:

Array from query ( [0] => O45527 [1] => P97387 [2] => Y49437 )

Array from array_dif ( [0] => ‘P97387’ [1] => ‘O45527’ [2] => ‘Y49437’ )
all items are the same right..

print_r($dif); should return array()

Answer 1

Use array_diff – it Computes the difference of arrays

Just convert your strings in to array using explode and use array_diff

Example :

<?php

$array1=explode(",",$string);
$array2=explode(",",$yourstring_of_db_column);
$array1 = array("x", "y", "z");
$array2 = array( "y","z");
$result = array_diff($array1, $array2);

print_r($result);
?>

Note : Two elements are considered equal if and only if (string) $elem1 === (string) $elem2. In words: when the string representation is the same.

Array from query ( [0] => O45527 [1] => P97387 [2] => Y49437 )

Array from array_dif ( [0] => ‘P97387’ [1] => ‘O45527’ [2] => ‘Y49437’ )

so O45527 and ‘O45527’ are different ans same for all that is why it’s returning whole array. Try to cast elemet values in same datatype.