# Monday, September 28, 2009

SQL Server Stored Procedure to disable / enable all foreign keys and constraints in a database

I've been doing a bit of batch archiving work, and needed a nice and quick way to disable foreign keys and other constraints without actually removing them.  I found a nice article on disabling all constraints in a database, and thought I'd just take it one step further by making it into a Stored Procedure, and adding a parameter to toggle whether the constraints are enabled or disabled.

Nice and easy.  Here's the script.


USE [YOURDBNAME]
GO

IF  EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[usp_SetDBTableConstraints]') AND type in (N'P', N'PC'))
DROP PROCEDURE dbo.usp_SetDBTableConstraints
GO

CREATE PROCEDURE dbo.usp_SetDBTableConstraints(@Enable BIT)

AS

/*** DISABLE/ENABLE ALL TABLE CONSTRAINTS ************************

This script will disable all constraints on all tables within the database
that it is run in.

************************************************************/

SET NOCOUNT ON
SET ROWCOUNT 0 

DECLARE @Count INT
DECLARE @String NVARCHAR (1000)
DECLARE @ConstraintName VARCHAR(128)
DECLARE @TableName VARCHAR(128)

--Find all constraints and their respective tables from the sysobjects table and place into a temp table.
--Primary Key and Unique Constraints via Unique Indexes are not disabled through this command
--You should use the ALTER INDEX...DISABLE command in SQL Server 2005
SELECT 
        name                     AS constraintname,
        object_name(parent_obj)  AS tablename 
INTO #Const_Table
FROM sysobjects s 
where xtype in ('F')

SELECT @Count = Count(*) FROM #Const_Table

--Setting the rowcount to one allows for one row from the temp table to be picked off at a time.
--Used as an alternative to a cursor.
SET ROWCOUNT 1

--Loop until all rows in temp table have been processed.
WHILE @Count > 0
BEGIN
    --The rowcount of one ensures that only one tablename and constraint name is picked.
    SELECT @TableName = TableName, @ConstraintName = ConstraintName
    FROM #Const_Table

    --Build execution string to disable constraint.
    IF @Enable = 1 
        SET @String = 'ALTER TABLE ['+ @tablename + '] CHECK CONSTRAINT [' + @constraintname +']'
    ELSE
        SET @String = 'ALTER TABLE ['+ @tablename + '] NOCHECK CONSTRAINT [' + @constraintname +']'

    --Execute the SQL
    EXEC sp_executesql @string

    --Remove this row from the temp table, since it has now been processed.
    DELETE FROM #Const_Table WHERE ConstraintName = @ConstraintName and TableName = @TableName

    SET @Count = @Count - 1
END -- Loop

SET ROWCOUNT 0

DROP TABLE #Const_Table
 

GO
SQL Server
posted on Monday, September 28, 2009 12:34:45 PM (AUS Eastern Standard Time, UTC+10:00)  #    Comments [0]
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