T-SQL:通过连接选择要删除的行

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问题描述

场景:

假设我有两个表，TableA 和 TableB.TableB的主键是单列(BId)，是TableA中的外键列.

Let's say I have two tables, TableA and TableB. TableB's primary key is a single column (BId), and is a foreign key column in TableA.

在我的情况下，我想删除 TableA 中与 TableB 中特定行链接的所有行:我可以通过联接来做到这一点吗?删除从连接中拉入的所有行?

In my situation, I want to remove all rows in TableA that are linked with specific rows in TableB: Can I do that through joins? Delete all rows that are pulled in from the joins?

DELETE FROM TableA 
FROM
   TableA a
   INNER JOIN TableB b
      ON b.BId = a.BId
      AND [my filter condition]

或者我被迫这样做:

DELETE FROM TableA
WHERE
   BId IN (SELECT BId FROM TableB WHERE [my filter condition])

我问的原因是在我看来，第一个选项在处理更大的表格时会更有效.

The reason I ask is it seems to me that the first option would be much more effecient when dealing with larger tables.

谢谢！

推荐答案

DELETE TableA
FROM   TableA a
       INNER JOIN TableB b
               ON b.Bid = a.Bid
                  AND [my filter condition]

应该可以

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