mysql - 编写一个 Select 查询以从另一个表中扣除一个表

Question

我对如何编写以下查询有点困惑：

我有两张桌子

tbl_one
ID      TEXT
1       test1
2       test2
3       test3
4       test4
5       test5

和

tbl_two
ID      userID      tblone_ID
1       50          1
2       100         1
3       100         2

我正在寻找未出现在 tbl_two 中但针对特定用户的 tbl_one 行。

例如通过下面的选择：

select * from tbl_one, tbl_two 
where (tbl_two.tblone_ID !=tbl_one.ID and tbl_two.userID==50) 

我的愿望结果将是

Desire resalt:
ID      TEXT
2       test2
3       test3
4       test4
5       test5

Answer 1

SELECT  a.*
FROM    tableA a
        LEFT JOIN tableB b
          on a.ID = b.tblone_ID AND
              b.userID = 50
WHERE   b.tblone_ID IS NULL

• SQLFiddle 演示

Answer 2

select * from tbl_one where tbl_one.ID not in ( Select tblone_ID
FRom tbl_two where userID=50)

SELECT * from tbl_one inner Join tbl_two on tbl_one.ID !=tblone_ID  where userID=50

Answer 3

select * 
from tbl_one 
where ID not in (select tblone_ID 
                 from tbl_two 
                 where userID = 50) 

Answer 4

SELECT * FROM tbl_one
LEFT JOIN tbl_two on tbl_one.ID = tbl_two.tblone_ID
WHERE tbl_one.ID IS NULL AND tbl_two.userID = 50

Answer 5

你可以试试这个

select * from tbl_one t1 
where t1.id not in (select tblone_id from tbl_two where tbl_two.userid=50)