如何刪除表1中不存在的行

Question

嘿，你好，你需要你的幫助，我很多嘗試，現在我累了找不到出路。

我有兩個表&我沒有內部聯接要刪除的那些行，外國ID不存在於表2，下面我已經通過結構提到..

表1

 Column A(Foreign)  Column B 

    record A    Some thing 
    record B    Some thing 
    record c    Some thing 

表2

 Column A(Foreign)  Column B 

    record A    Some thing 
    record B    Some thing 

現在其實我想刪除不在表2中的記錄C ..是否有任何出路？

Answer 1

DELETE FROM `Table 1` t1 
WHERE NOT EXISTS (
    SELECT 1 FROM `Table 2` t2 
    WHERE t2.`Column A(Foreign)` = t1.`Column A(Foreign)` 
) 

可怕的表和列名，順便

演示在這裏 - http://sqlfiddle.com/#!2/4c2d8/1

Answer 2

這工作：

DELETE VM.* FROM `Table1` AS VM 
LEFT JOIN `Table2` AS VL 
ON VL.`Column A(Foreign)` = VM.`Column A(Foreign)d` 
WHERE VL.`Column A(Foreign)` IS NULL 

Answer 3

試試這個，工作。

http://sqlfiddle.com/#!2/d5f02/1

create table t1 (
    a varchar(16), 
    b varchar(16) 
); 

create table t2 (
    a varchar(16), 
    b varchar(16) 
); 

insert into t1 values 
('record A', 'Some thing'), 
('record B', 'Some thing'), 
('record c', 'Some thing'); 

insert into t2 values 
('record A', 'Some thing'), 
('record B', 'Some thing'); 

delete t1 
FROM t1 left outer join t2 
ON t1.a = t2.a 
where t2.a is null