function DatabaseSelectSubqueryTestCase::testJoinSubquerySelect

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

File

core/modules/simpletest/tests/database_test.test, line 1778

Database tests.

Class

DatabaseSelectSubqueryTestCase

Test case for sub-selects 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.');
}