MySQL search between 2 dates

Question

I am having a wierd issue on a query, I am simply doing a search using 2 dates, I have all the dates in the database formatted in 2012-12-02 00:00:00 mysql format, but it is simply ignoring the AND cslblicstat = '10' AND wcxdate BETWEEN '$date1' AND '$date2' and giving me anything that has the matching class.

$user = $session->username;
if(isset($_POST['carrier'])){
$carrier = $_POST['carrier'];
$class[] = $_POST['class'][0];
$date1 = $_POST['date1'];
$date1 = date("Y-m-d 00:01", strtotime($date1));
$date2 = $_POST['date2'];
$date2 = date("Y-m-d 59:59", strtotime($date2));

 foreach( $class as $key){
 $query =   "SELECT * FROM leads WHERE class1 = '$key' OR class2 = '$key' OR class3 = '$key' OR class4 = '$key' OR class5 = '$key' OR class6 = '$key' OR class7 = '$key' OR class8 = '$key' OR class9 = '$key' OR class10 = '$key' OR class11 = '$key' OR class12 = '$key' AND user = '' AND wccompcode = '$carrier' AND cslblicstat = '10' AND wcxdate BETWEEN '$date1' AND '$date2' LIMIT 100";
$sellead = mysql_query($query)or die(mysql_error());
while($leads = mysql_fetch_array($sellead)){

    $arrayl[] = $leads;
    $rowid = $leads['ID'];
    $update = mysql_query("UPDATE leads SET user = '$user' WHERE ID = '$rowid'")or die(mysql_error());

}
}
}

Answer 1

In SQL, AND operator has higher precedence than OR . I guess that you just need to put the ORed conditions into parentheses:

SELECT * 
FROM leads
WHERE (class1 = '$key' OR class2 = '$key' OR ... OR class12 = '$key')
  AND user = '' 
  AND wccompcode = '$carrier' 
  AND cslblicstat = '10' 
  AND wcxdate BETWEEN '$date1' 
                  AND '$date2' 
LIMIT 100   

When in doubt about precedence of operators, use parenthesis (or consult the manual).

You could also write that condition with IN :

WHERE '$key' IN (class1, class2, ... , class12)
  AND user = ''
  ---

Answer 2

In MySQL AND is evaluated before OR. So your WHERE clause is equivalent to this:

SELECT 1 OR 0 AND 0;

The result is true:

+--------------+
| 1 OR 0 AND 0 |
+--------------+
|            1 |
+--------------+

Also, a syntactically simpler method of expressing your OR conditions would be something like this:

WHERE '$key' IN ( class, class2, class3, ... ) AND ... ;

But anytime you have columns like that with numbers, what it really means is that your schema can be improved.