In order to achieve this, you have to construct the grouped clause within a single call to the where method.
If both values of conditions are the same, you can do this:
$select->where('client_email = ? OR client_email_alt = ?', $client_email)If there are multiple placeholders within the string, the DB adapter's quoteInto method will replace all placeholders with the provided value.
If you need to group an OR with different values for each field, you have to manually quote the values. It's a bit more complex:
$select->where(
$db->quoteInto('client_email = ?', $email1).' OR '. $db->quoteInto('client_email_alt = ?', $email2));// $db is your instance of Zend_Db_Adapter_*// You can get it from a Zend_Db_Table_Abstract //subclass by calling its getAdapter() method