Question

我希望找到练习和游戏表中不存在的条目，但我无法使用第二个不在语句中。还有其他办法吗？

 select VenueID from Venue
 where VenueID not in (select VenueID from Practice)
 and not in (select VenueId from Game)

Answer 1

您需要重复NOT IN语句，包括列名：

SELECT VenueID
FROM Venue
WHERE VenueID NOT IN (SELECT VenueID FROM Practice) AND
      VenueID NOT IN (SELECT VenueId FROM Game)
       ^^^ you omitted the second column name

使用NOT IN的另一种方法是做两个左连接：

SELECT VenueID
FROM Venue t1
LEFT JOIN Practice t2
    ON t1.VenueID = t2.VenueID
LEFT JOIN Game t3
    ON t1.VenueID = t3.VenueID
WHERE t2.VenueID IS NULL AND
      t3.VenueID IS NULL

Answer 2

您在第二个not in中缺少列名称（每个条件都是单独的，语法是＆lt; column＆gt; NOT IN＆lt; value set＆gt; ）：

select VenueID from Venue
where VenueID not in (select VenueID from Practice)
and VenueID not in (select VenueId from Game)
--  ^^^^^^^

无法在语句中使用多个

2 个答案: