php - MYSQL|来自两个表的请求2

Question

我有 2 个 Mysql 表:

A(用户表):

id用户名房间

1    User1    1 
2    User2    1
3    User3    1

B(被阻止的用户):

id   username
1    User3

我的请求在这里(我想获取 User1 和 User2，因为 User3 处于阻塞状态):

SELECT A.id, A.username FROM `table1` A, `table2` B 
  WHERE A.roomid = 1 AND A.username != B.username

但这是错误的请求。谢谢!

Answer 1

您需要加入两个表A和B，例如

SELECT A.id, A.username FROM `table1` A
JOIN `table2` as B ON `table1`.id = `table2`.id
WHERE A.room = 1 AND A.username != B.username

或者您的列名称是 room 而不是 roomid

SELECT A.id, A.username FROM `table1` A, `table2` B 
WHERE A.room = 1 AND A.username != B.username