Question

The code below won’t work because of this line $params=array($data);. It needs something other than $data. Or it needs something to happen with $data prior to this line.

If the line is written as $params=array(“A”, “B”, “C”, “D”); then it works great, but my array is in the $data variable, not written out like that. If there is a way to get the array converted to being written out like that, that would work too.

The end result should show every possible combination (not permutation) of the contents of the array. Like in the example above it shows ABC, BD, etc.

$data = mysql_query('SELECT weight FROM my_table WHERE session_id = "' . session_id() . '"'); 

$params=array($data);

$combinations=getCombinations($params);
function getCombinations($array)
{
    $length=sizeof($array);
    $combocount=pow(2,$length);
for ($i=1; $i<$combocount; $i++)
    {

$binary = str_pad(decbin($i), $length, "0", STR_PAD_LEFT);
        $combination='';
        for($j=0;$j<$length;$j++)
        {
            if($binary[$j]=="1")
                $combination.=$array[$j];
        }
        $combinationsarray[]=$combination;
        echo $combination."&lt;br&gt;";
    }
    return $combinationsarray;
} 

Answer 1

mysql_query() only returns a result resource ID. To retrieve data, you must use one of the “fetch” commands, for example

$params = array();
while ($row = mysql_fetch_assoc($data)) {
    $params[] = $row['weight'];
}

Also, your query is possibly vulnerable to SQL injection. I wouldn’t implicitly trust the value from session_id(). I’m not entirely sure of this but it may simply retrieve the value from the session cookie.

At the very least, sanitise the value with mysql_real_escape_string(). A more robust solution which would bring your code out of the dark ages would be to use PDO and parameter binding.