Zend 2.1: Is it possible to do a multiple schema join via Db>Sql>Select

Question

I'm pretty new to Zend and having a go with Zend Select abstraction. I have hit a bit of a problem when trying to create a query which joins another table from a different schema.

The mySql query I'm trying to produce is:

SELECT * FROM `assets`
JOIN `projects`
ON `assets`.project_id = `projects`.id
JOIN `secondSchema`.`users` AS `users`
ON `users`.id = `projects`.user_id
WHERE `projects`.id = ?
AND `users`.id = ?

working with Zend/Db/Sql/Sql/Select I can setup the following select builder, but I am struggling with setting another schema in the resulting Sql statement:

$select = $this->_sqlBuilder->select();
    $select->from('assets');
    $select->join(
        'projects',
        'projects.id = assets.project_id'
    );
    $select->join(
        'users',
        'users.id = projects.user_id'
    );
    $select->where->equalTo('assets.project_id', $projectID);
    $select->where->equalTo('users.id', $userId);

I have tried using \Zend\Db\Sql\TableIdentifier to set the schema but the original schema in the adapter is then replaced, there doesn't look like a way to have both schemas present in the query.

Is there anyway to do this using Sql/Select or am I going about this the wrong way with Zend Db?

Thanks for the help

Answer 1

The issue is occurring because of the way the Select class escapes quotes.

$select->join("database2.table2", "database2.table2.id = table.id")

Is rendered as:

SELECT 'table'.*, 'database2.table2'.* FROM 'table' INNER JOIN 'database2.table2' ON 'database2'.'table2'.'id' = 'table'.'id'

Note the inconsistant and incorrect quoting around "database2.table2".

Updating lines 596, 599, 624, 625 in \Zend\Db\Sql\Select to replace the "quoteIdentifier" method with "quoteIdentifierInFragment" renders the query correctly and allows a cross database join to be performed.

I've submitted an issue report to Zend as I don't believe the current behaviour is intended so hopefully it will be updated in a future build. For now it's easy enough (though admittedly a little dirty) to update the class manually.

https://github.com/zendframework/zf2/issues/4307

Answer 2

Looks like this isn't actually possible using Db\Select sadly. However you can create some nice vendor portable sql straight from the adapter. http://framework.zend.com/manual/2.1/en/modules/zend.db.adapter.html

Thanks.