How to alter constraint in sql server

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Hello,

ALTER TABLE test3 alter CONSTRAINT const_name FOREIGN KEY REFERENCES test2(test) on delete cascade

i am getting error can you please help me.

thanks in advance..

Posted 3-Oct-11 1:49am

K N R

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nagendrathecoder 3-Oct-11 7:56am

Mention what error you are getting.

Om Prakash Pant 3-Oct-11 8:58am

check the following kb article on managing FKeys:
http://msdn.microsoft.com/en-us/library/ms177463(v=sql.90).aspx

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Manfred Rudolf Bihy · Answer 1 · 2011-10-03T02:57:00

If you'd taken care to read the MSDN page on the ALTER TABLE command (ALTER TABLE[^]) you would have noticed that the commands BNF description does not allow for it. All you can do would be to DROP the constraint an reinstate it with the correct parameters.

Example of adding a constraint to an existing table:

SQL

ALTER TABLE [wm].[TABLE_NAME]  WITH NOCHECK ADD  CONSTRAINT [FK_TABLE_NAME_PARENT_TABLE_NAME] FOREIGN KEY([FOREIGN_KEY])
REFERENCES [wm].[PARENT_TABLE_NAME] ([PRIVATE_KEY])
ON DELETE CASCADE

Cheers!

sachin10d · Answer 2 · 2011-10-03T19:49:00

Solution 2

We cannot alter the constraint, only thing we can do is drop and recreate.
DROP and ADD constraint script

SQL

ALTER TABLE test3 DROP CONSTRAINT const_name 
GO

ALTER TABLE test3 ADD CONSTRAINT const_name FOREIGN KEY(ColName) REFERENCES test2(test) on delete cascade
GO

Posted 3-Oct-11 19:49pm

sachin10d