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sql - 具有子查询奇怪行为的 DELETE 语句

转载 作者:行者123 更新时间:2023-12-02 01:47:19 32 4
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我有 2 个表正在执行删除语句。当我选择列名无效的列时,它会抛出错误。但是当我使用第一个表的列名时,它只会删除记录。

//查询:

CREATE TABLE FOO (ID INT)
GO
CREATE TABLE FOOBAR (NUMBER INT)
GO

INSERT INTO FOO VALUES(1)
INSERT INTO FOO VALUES(2)
INSERT INTO FOO VALUES(3)
INSERT INTO FOOBAR VALUES(1)
GO

-- The following will raise an error
SELECT ID FROM FOOBAR WHERE NUMBER = 1
GO
--Server: Msg 207, Level 16, State 3, Line 1
--Invalid column name 'ID'.


-- The following statement will delete the entire table
DELETE FROM FOO WHERE ID IN
(SELECT ID FROM FOOBAR WHERE NUMBER = 1)
GO
--(3 row(S) affected)

当我使用别名时,它工作正常。是错误还是其他原因?

这是怎么发生的?

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