php - 如果不在表 1 中，则从表 2 中删除，基于 2 个字段

Question

他们都有 fileId 和 userId 字段

表 1：fileId userId

表2：fileId userId

如果它们不在表 1 中，我想删除表 2 中的所有行，基于它们的 fileId 和 userId .. 不仅仅是一个字段，而是两个字段......

亲切的问候，J

Answer 1

delete from table2 
where fileid not in (select fileid from table1)
and userId not in (select userId from table1)

Answer 2

看看这个方法。测试工作。

CREATE table table1(field varchar(10),userid varchar(20));
CREATE table table2(field varchar(10),userid varchar(20));

insert into table1 values('10','vish');
insert into table1 values('11','atul');
insert into table1 values('12','nish');

insert into table2 values('10','vish');
insert into table2 values('11','atul');
insert into table2 values('13','paul');
insert into table2 values('14','ganesh');

DELETE from table2
WHERE NOT exists 
(select field+userid from table1 t1 where t1.field+userid = table2.field+userid);

SELECT * FROM table2;

Answer 3

DELETE FROM table2 WHERE userId NOT IN (SELECT userId from table1) AND 
                         fileId NOT IN (SELECT fileId from table1)

Answer 4

TRY（假设id是两个表的主键）

DELETE FROM table2
WHERE id NOT IN ( 
        SELECT 'id' FROM table1 t1 
        INNER JOIN table2 t2 ON ( t1.field=t2.filed AND t1.userid = t2.userid)
        )