Complex WHERE clause with Zend_Db using multiple AND OR operators

Question

I want to generate this complex WHERE clause in Zend_Db:

SELECT * 
FROM 'products' 
WHERE 
    status = 'active' 
    AND 
    (
        attribute = 'one' 
        OR 
        attribute = 'two' 
        OR 
        [...]
    )
;

I've tried this:

$select->from('product');
$select->where('status = ?', $status);
$select->where('attribute = ?', $a1);
$select->orWhere('attribute = ?', $a2);

and that produced:

SELECT `product`.* 
FROM `product` 
WHERE 
    (status = 'active') 
    AND 
    (attribute = 'one') 
    OR 
    (attribute = 'two')
;

I did figure out one method of making this work but I felt it was sort of 'cheating' by using PHP to combine the "OR" clauses first and then combine them using Zend_Db where() clause. PHP code:

$WHERE = array();
foreach($attributes as $a):
    #WHERE[] = "attribute = '" . $a . "'";
endforeach;
$WHERE = implode(' OR ', $WHERE);

$select->from('product');
$select->where('status = ?', $status);
$select->where($WHERE);

That produced what I was looking for. But I'm curious if there's an "official" way of getting that complex WHERE statement (which really isn't too complex, just adding some parenthesis) with using the Zend_Db tool, instead of combining it in PHP first.

Cheers!

Answer 1

This would be the 'official' way to get you the parentheses as specified (see Example #20 in the Zend_Db_Select documentation):

$a1 = 'one';
$a2 = 'two';
$select->from('product');
$select->where('status = ?', $status);
$select->where("attribute = $a1 OR attribute = $a2");

So, what you are doing does seem reasonable, given that you do not know how many attributes you have ahead of time.

Answer 2

If using the chosen answer you would need to remember to quote the values before constructing the query to guard against SQL injection.

Another option that uses Zend Db Select to create the query and also quotes the values would be to do it in 2 stages:

/// we just use this select to create the "or wheres"
$select1->from('product');
foreach($attributes as $key => $a) {
    if ($key == 0) {
    /// we don't want "OR" for first one
        $select1->where("attribute = ?", $a);
    } else {
        $select1->orWhere("attribute = ?", $a);
    }   
}

/// now we construct main query
$select2->from('product');
$select2->where('status = ?', $status);
$select2->where(implode(' ', $select1->getPart('where')));

This way Zend Db Select does all the SQL generatation. An old question but hopefully this idea might be of use to someone with a similar problem.