function DatabaseSelectSubqueryTestCase::testJoinSubquerySelect

Test that we can use a subquery in a JOIN clause.

File

modules/simpletest/tests/database_test.test, line 1951

Class

DatabaseSelectSubqueryTestCase

Test case for subselects in a dynamic SELECT query.

Code

function testJoinSubquerySelect() {
    // Create a subquery, which is just a normal query object.
    $subquery = db_select('test_task', 'tt');
    $subquery->addField('tt', 'pid', 'pid');
    $subquery->condition('priority', 1);
    // Create another query that joins against the virtual table resulting
    // from the subquery.
    $select = db_select('test', 't');
    $select->join($subquery, 'tt', 't.id=tt.pid');
    $select->addField('t', 'name');
    // The resulting query should be equivalent to:
    // SELECT t.name
    // FROM test t
    //   INNER JOIN (SELECT tt.pid AS pid FROM test_task tt WHERE priority=1) tt ON t.id=tt.pid
    $people = $select->execute()
        ->fetchCol();
    $this->assertEqual(count($people), 2, 'Returned the correct number of rows.');
}