Sql (zend db select) of multiple selects

Question

I need a bit of help. I have (reference?) table with columns: id , user_id , key , value

It is pretty much a user profile table and I would like to have SQL (I am using zend db table, but general SQL help will do) where I get "all 'user_id's where 'key' is somekey and 'value' is somevalue of that user_id but only if it also matches where 'key' is otherkey and 'value' is othervalue".

In other words I want to get users that have shoes of maker NIKE and color BLACK. therefore 'key' is shoecolor and 'value' is BLACK and also another row with same user_id has 'key' is shoemaker and 'value' is NIKE.

This is what I could come up with, but doesn't work.

SELECT `user_profiles`.* FROM `user_profiles` WHERE
(`key` = 'shoecolor' AND `value` = 'BLACK') AND
(`key` = 'shoemaker' AND `value` = 'NIKE')

In case someone is knowledgable in zend db:

$where = array('shoecolor' => 'BLACK', 'shoemaker' => 'NIKE');
    foreach ($where as $key => $value) {
        $sql = $db->quoteInto('key = ?', $key);
        $sql .= ' AND ' . $db->quoteInto('value = ?', $value);
        $select->where($sql);
    }
    // make unique result
    //$select->groupBy('user_id');
    $resultSet = $zendTableInstance->fetchAll($select);

Please Help. Thanx.

Answer 1

Because the key/value pair is in the row, your query is looking for a key that is 3 AND 4. No value can be 3 and 4 at the same time ;)

SELECT user_profiles.* FROM user_profiles WHERE (key = 3 AND value = 21) AND (key = 4 AND value = 55)

will not work.

You could do a join on yourself, and check for these values?

SELECT user_profiles.* 
FROM user_profiles up1
  JOIN user_profiles up2 ON up1.user_id = up2.user_id
WHERE 
  (up1.key = 3 AND up1.value = 21) 
  AND (up2.key = 4 AND up2.value = 55)