23. 다음 중 유효한 SQL 문장이 아닌 것은?
- 1SELECT * FROM Lawyers WHERE firmName LIKE'% and %';
- 2SELECT firmLoc, COUNT(*) FROM Firms WHEREemployees < 100;
- 3SELECT COUNT(*) FROM Firms WHERE employees< 100;
- 4SELECT firmLoc, SUM(employees) FROM FirmsGROUP BY firmLoc WHERE SUM(employees) < 100;