Implements hook_query_TAG_alter() for tag 'store_global_test_query'.
function field_test_query_store_global_test_query_alter($query) {
// Save the query in a global variable so that it can be examined by tests.
// This can be used by any test which needs to check a query, but see
// FieldSqlStorageTestCase::testFieldSqlStorageMultipleConditionsSameColumn()
// for an example.
$GLOBALS['test_query'] = $query;
}