MySQL多于1行错误

Question

这是我输入的内容，我必须将 EXCEPT 替换为“NOT IN”。这样就解决了一个错误，但现在它返回多于 1 行。我不确定那有多糟糕。我刚刚开始了解 MySQL 并尝试书中的示例。

SELECT S.sname 
FROM suppliers S 
WHERE (
  (SELECT P.pid FROM parts P) NOT IN 
  (SELECT C.pid FROM catalog C WHERE C.sid = S.sid)
);

ERROR 1242 (21000): Subquery returns more than 1 row

Answer 1

SELECT S.sname 
FROM suppliers S 
WHERE NOT EXISTS(
SELECT P.pid FROM parts P, catalog C 
WHERE P.pid = C.pid AND C.sid = S.sid)
);