Question

以下查询返回我要查找的内容。

SELECT * from meetings where meetings.date = '2018-03-12';

但是，下面给出的是

未知专栏＆＃39;'2018＆＃39;在＆＃39; where子句＆＃39;

SELECT roomNumber 
FROM rooms 
WHERE NOT EXISTS
( SELECT *
FROM meetings 
WHERE rooms.roomNumber = meetings.room
AND meetings.date = ‘2018-03-12’ );

我在没有单引号的情况下尝试了2018-03-12，并且它有效。但是，这不会返回正确的记录集。我正在寻找当天没有开会的可用房间。

Answer 1

试试这个

SELECT roomNumber 
FROM rooms 
WHERE NOT EXISTS
( SELECT *
FROM meetings 
WHERE rooms.roomNumber = meetings.room
AND meetings.date = '2018-03-12' );

这基本上是@BoarGules评论的修正，你使用的是智能引号：‘2018-03-12’而不是单引号：'2018-03-12'

Answer 2

SELECT roomNumber 
FROM rooms 
WHERE NOT EXISTS IN 
( SELECT rooms.roomNumber
FROM meetings 
WHERE rooms.roomNumber = meetings.room
AND meetings.date = 2018-03-12 );

尝试使用此查询

＆＃39; where子句＆＃39;中的未知列日期

2 个答案: