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

File

drupal-7.x/modules/simpletest/tests/database_test.test, line 1760

Class

DatabaseSelectSubqueryTestCase

Test case for subselects in a dynamic SELECT query.

Code

function testConditionSubquerySelect() {
  // Create a subquery, which is just a normal query object.
  $subquery = db_select('test_task', 'tt');
  $subquery->addField('tt', 'pid', 'pid');
  $subquery->condition('tt.priority', 1);

  // Create another query that joins against the virtual table resulting
  // from the subquery.
  $select = db_select('test_task', 'tt2');
  $select->addField('tt2', 'task');
  $select->condition('tt2.pid', $subquery, 'IN');

  // The resulting query should be equivalent to:
  // SELECT tt2.name
  // FROM test tt2
  // WHERE tt2.pid IN (SELECT tt.pid AS pid FROM test_task tt WHERE tt.priority=1)
  $people = $select->execute()->fetchCol();
  $this->assertEqual(count($people), 5, 'Returned the correct number of rows.');
}