Question

如何在查找B.R = 1的所有匹配时，将两个字段A.P和A.C与表B的B.P和B.C进行比较时，如何从表A中删除？

实际上以下任何一项工作都没有，但它应该朝着方向发展，遗憾的是我无法弄清楚如何......

DELETE FROM A WHERE (A.P = B.P AND A.C = B.C where B.C = 1)

DELETE FROM A WHERE (SELECT B.P, B.C FROM B WHERE B = 1)

Answer 1

DELETE FROM A
FROM A INNER JOIN B ON A.P = B.P AND A.C = B.C
WHERE B.C = 1

双重FROM有时会让人失望。

Answer 2

DELETE
FROM    A
WHERE   EXISTS
        (
        SELECT  NULL
        FROM    b
        WHERE   b.p = a.p
                AND b.c = a.c
                AND b.r = 1
        )

Answer 3

DELETE FROM A WHERE A.Id IN 
(SELECT A.Id FROM A INNER JOIN B ON A.P = B.P WHERE B.C = 1)

Answer 4

您要求删除A中的所有记录那个C值=表B中行中的C值，C = 1且P值相同？

这与删除A中具有C值= 1 [和表B中的相同P值]中的所有行相同。

所以试试这个：

Delete A 
Where C = 1 
   And Exists
      (Select * From B
       Where C = 1 
         And P = A.P)

Answer 5

这样的事情会起作用

DELETE FROM A
FROM A
 INNER JOIN B ON A.P = B.P AND A.C = B.C AND B.R = 1

SQL - 如何从另一个表引用时从一个表中删除？

5 个答案: