Enabling and disabling all constraints on a table in SQL Server

These procedures are very useful when you need to load bulk data and you know the data is correct -- but you do not need the foreign keys and check constraints to interfere. You might also use them when you want to change key values and don't want the constraints to get in your way.

So, the following procedure will disable/enable all constraints for a given parametric table: 

CREATE PROCEDURE sp_ConstraintState 
               @TblName   VARCHAR(128),
           @State BIT = 1
AS
DECLARE @SQLState VARCHAR(500)
IF @State = 0
        BEGIN
             SET @SQLState = 'ALTER TABLE '+ @TblName + ' NOCHECK CONSTRAINT ALL'
     END
ELSE
   BEGIN
                    SET @SQLState = 'ALTER TABLE ' + @TblName + ' CHECK CONSTRAINT ALL'
   END
EXEC (@SQLState)
go

For example:

exec sp_ConstraintState  'products',0

...will disable all constraints on the products table in the Northwind database.

The following procedure will use sp_constraintState to disable all constraints in the database: 

 
 Create proc sp_disable_all_const_in_db 
as
  'exec sp_MsForEachTable 'sp_ConstraintState ''?'',0
go
For example, to disbale all constraints in the database: 
EXEC sp_disable_all_const_in_db

About the author

    Requires Free Membership to View

    Login

Eli Leiba works at the Israel Electric Company as a senior application DBA in Oracle and Microsoft SQL Server. He has certifications from Microsoft and BrainBench in Oracle and SQL Server database administration and implementation. Mr. Leiba holds a B.S. in computer science and has 11 years of experience working in the database field. Additionally, Mr. Leiba teaches SQL Server DBA and development courses at the Microsoft CTEC and serves as a senior database consultant for several Israeli start-up companies.

For More Information

  • Feedback: E-mail the editor with your thoughts about this tip.
  • More tips: Hundreds of free SQL Server tips and scripts.
  • Tip contest: Have a SQL Server tip to offer your fellow DBAs and developers? The best tips submitted will receive a cool prize -- submit your tip today!
  • Ask the Experts: Our SQL, database design, Oracle, SQL Server, DB2, metadata, and data warehousing gurus are waiting to answer your toughest questions.
  • Forums: Ask your technical SQL Server questions--or help out your peers by answering them--in our active forums.
  • Best Web Links: SQL Server tips, tutorials, and scripts from around the Web.

This was first published in February 2005

Join the conversationComment

Share
Comments

    Results

    Contribute to the conversation

    All fields are required. Comments will appear at the bottom of the article.

    Disclaimer: Our Tips Exchange is a forum for you to share technical advice and expertise with your peers and to learn from other enterprise IT professionals. TechTarget provides the infrastructure to facilitate this sharing of information. However, we cannot guarantee the accuracy or validity of the material submitted. You agree that your use of the Ask The Expert services and your reliance on any questions, answers, information or other materials received through this Web site is at your own risk.

    Back to top