Question

我想使用sqlcommand从相关表（具有相同外键ID的记录）中删除2条记录。是否有任何类似SCOPE_IDENTITY的方法返回最后一个ID已被删除？我不想使用ON DELETE CASCADE约束。有什么想法吗？

感谢。

Answer 1

如何在SQL Server中获取已删除的标识号：

让我们有一张员工表，其中一些员工记录与每位员工的唯一身份号码一起保存现在，假设由于某些原因从Employee表中删除了一些记录，现在我们想要从Employee表中删除所有已删除的记录，现在可能无法从表中删除记录，但我们可以获取唯一标识列表使用查询从Employee表中删除记录。

-- Create Employee Table
Create Table EMPLOYEE( ID int,EmpID int,EmpName varchar(50))

-- Insert Sample data to the Employee table
INSERT INTO EMPLOYEE VALUES ( 1, 1, 'Aasish')
INSERT INTO EMPLOYEE VALUES ( 2, 1, 'Anita');
INSERT INTO EMPLOYEE VALUES ( 3, 1, 'Kabita');
INSERT INTO EMPLOYEE VALUES ( 4, 2, 'Raj');
INSERT INTO EMPLOYEE VALUES ( 5, 2, 'Babita');
INSERT INTO EMPLOYEE VALUES ( 6, 2, 'Geet');
INSERT INTO EMPLOYEE VALUES ( 7, 2, 'Krishh');
INSERT INTO EMPLOYEE VALUES ( 8, 3, 'Kabir');
INSERT INTO EMPLOYEE VALUES ( 9, 3, 'Rasmita');
INSERT INTO EMPLOYEE VALUES ( 10, 3, 'Sam');

-- Delete data from the Employee table
DELETE EMPLOYEE WHERE ID IN(1,10,12);

--- Retrive the Employee table data after deleting the records
SELECT ID FROM EMPLOYEE
--- Retrive the deleted unique identity numbers from the Employee table
WITH Missing (missnum, maxid)
AS
( 
SELECT 1 AS missnum, (select max(id) from EMPLOYEE) UNION ALL SELECT missnum + 1, maxid FROM Missing 
WHERE missnum < maxid
)
SELECT missnum FROM Missing 
LEFT OUTER JOIN EMPLOYEE e on e.id = Missing.missnum
WHERE e.id is NULL OPTION (MAXRECURSION 0);

通过从第一个返回的useng ID从两个相关表中删除

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