31. 以下哪項不是有效的SQL指令?
(A)SELECT * FROM Lawyers WHERE firmName LIKE '% and %';
(B)SELECT COUNT(*) FROM Firms WHERE employees < 100;
(C)SELECT firmLoc, COUNT(*) FROM Firms WHERE employees < 100;
(D)SELECT firmLoc, COUNT(*) FROM Firms WHERE employees < 100 GROUP BY firmLoc;
答案:登入後查看
統計: A(39), B(21), C(63), D(39), E(0) #2388706
統計: A(39), B(21), C(63), D(39), E(0) #2388706