Sets up tables for NULL handling.
function ensureSampleDataNull() {
db_insert('test_null')
->fields(array(
'name',
'age',
))
->values(array(
'name' => 'Kermit',
'age' => 25,
))
->values(array(
'name' => 'Fozzie',
'age' => NULL,
))
->values(array(
'name' => 'Gonzo',
'age' => 27,
))
->execute();
}