mysql - #1052 - where 子句中的列 id 不明确

Question

我正在尝试连接三个表，但不知道为什么此消息不断出现。下面是我的 SQL:

select*
FROM payment,customer,purchase
where cname = 'Ben Parker', AND cid = '21' AND pid = '12';

Answer 1

请使用 JOINS 代替 where 子句 https://www.w3schools.com/sql/sql_join.asp

select*
FROM payment p
JOIN customer c
ON c.cusid = p.cusid   --assuming cusid is present in both the tables
JOIn purchase pu
ON pu.payid = p.payid   --assuming payid is present in both the tables
where c.cusname = 'Ben Parker' AND c.cusid = '21' AND p.payid = '12';

如果您仍然想要按照自己的方式进行，那么这就是方法(不推荐)

select*
FROM payment p,customer c,purchase pu
where c.cusname = 'Ben Parker' AND c.cusid = '21' AND p.payid = '12';