[HOWTO] SQL for Multivalue check box

I have a table, called zipcodes, with zip codes. I have another table called affiliate with field “zip” defined as field type of “list”. This uses checkbox (multi value) “get options from database”, with zipcodes as the options and value. All is working fine. My question is around the SQL Where statement.

$sql = “zip=76016”;
list($affiliateRecords, $affiliateMetaData) = getRecords(array(
'tableName' => 'affiliate',
'where' => $sql,
'limit' => '1',
));

The database shows “zip” containing multiple values (from multi value checkbox). The data shows “76016 76092 76003” and my SQL where clause is not working. Any ideas? NOTE: the database actually has some additional characters between the zip codes. I think CMS uses this as separator chars.