Test that we can find a record with a NULL value.
function testNullCondition() {
$this
->ensureSampleDataNull();
$names = db_select('test_null', 'tn')
->fields('tn', array(
'name',
))
->isNull('age')
->execute()
->fetchCol();
$this
->assertEqual(count($names), 1, 'Correct number of records found with NULL age.');
$this
->assertEqual($names[0], 'Fozzie', 'Correct record returned for NULL age.');
}