Cascade delete in sql server

Question

Hi... I want to know on cascade delete with an example in sql server ? Please explain anyone ? Thanks.....

Priya Linge · Answer

Hi, Cascading deletes in SQL Server 1.SQL Server does so via foreign key constraints with the DELETE CASCADE flag set. 2.In the following example, after creating the objects and inserting some data, we delete a USR_ID from the parent data. After querying the child table (USER_PHONE) a second time, we can see that the cascading delete worked : 3.Example : CREATE TABLE USERS ( USR_ID int ,CONSTRAINT [PK_Temp_Users1] PRIMARY KEY CLUSTERED ([USR_ID]) ) CREATE TABLE USER_PHONE ( USR_ID int ,CONSTRAINT [PK_Temp_Users2] PRIMARY KEY CLUSTERED ([USR_ID]) ) ALTER TABLE [dbo].USER_PHONE WITH CHECK ADD CONSTRAINT [FK_Temp_UsersPhone_Users] FOREIGN KEY([USR_ID]) REFERENCES [dbo].[Users] ([USR_ID]) ON DELETE CASCADE GO INSERT INTO USERS SELECT 1 UNION SELECT 2 UNION SELECT 3 INSERT INTO USER_PHONE SELECT 1 UNION SELECT 2 UNION SELECT 3 SELECT * FROM USER_PHONE DELETE USERS WHERE USR_ID=2 SELECT * FROM USER_PHONE DROP TABLE USER_PHONE DROP TABLE USERS Please check below link for more information. http://www.java2s.com/Code/SQLServer/Constraints/DELETECASCADEandUPDATECASCADE.htm Hope this will help you. Thanks.

Vineet Kumar Saini · Answer

Thanks all my Dear....

Jignesh Trivedi · Answer

hi vineet, Please try with create table script. CREATE TABLE test_child (SUB1 INT, [NO] int, FOREIGN KEY ([NO]) REFERENCES Test_parent ON DELETE CASCADE) Please refer the below link http://msdn.microsoft.com/en-us/library/ms186973(SQL.90).aspx

Satyapriya Nayak · Answer

Hi Vineet, Please refer the below link http://rudesyle.wordpress.com/2008/01/28/cascading-deletes-in-sql-server/ http://www.java2s.com/Code/SQLServer/Constraints/DELETECASCADEandUPDATECASCADE.htm Thanks

Cascade delete in sql server

Answers (4)