Question

我有两张桌子

 tbl_cid
-------------------------
| cid | sid | rid | dt  |
-------------------------
| 1   | 101 | 103 | xxx |
| 6   | 104 | 101 | xxx |
| 8   | 104 | 103 | xxx |
| 9   | 105 | 104 | xxx |
-------------------------

tbl_uid
--------------
| uid | name |
--------------
| 101 | john |
| 103 | tim  |
| 104 | paul |
| 105 | alex |
--------------

SELECT u.name, c.cid, c.sid, c.rid FROM tbl_cid c
JOIN tbl_uid u on u.uid = c.sid 
WHERE c.sid = 101 OR c.rid = 101

Expected result:
--------------------
| cid | uid | name |
--------------------
| 1   | 103 | tim  |
| 6   | 104 | paul |
--------------------

我以不同的方式尝试过，但无法找到它。假设我在tbl_cid中搜索101，如果sid有101则加入rid，如果rid有101则加入sid。任何帮助是极大的赞赏。谢谢

Answer 1

我认为这就是你要找的东西：

select tbl_cid.cid, tbl_uid.uid, tbl_uid.name
from tbl_cid, tbl_uid
where (tbl_cid.sid = tbl_uid.uid AND tbl_cid.rid = 101) OR (tbl_cid.rid = tbl_uid.uid AND tbl_cid.sid = 101);

Result:
--------------------
| cid | uid | name |
--------------------
| 1   | 103 | tim  |
| 6   | 104 | paul |
--------------------

Answer 2

我实际上不同意@wdika，你应该使用连接，因为使用带有两个表的where子句只是隐式地进行连接。

SELECT u.name, c.cid, c.sid, c.rid FROM tbl_cid c
    JOIN tbl_uid u on u.uid = c.sid or u.uid = c.rid
    WHERE (c.sid = 101 OR c.rid = 101) and u.uid != 101;

加入使用案例陈述

2 个答案: