Disable Foreign Key Constraints with INSERT and UPDATE Statements

You can disable a foreign key constraint during INSERT and UPDATE transactions in SQL Server 2012 by using SQL Server Management Studio or Transact-SQL. Use this option if you know that new data will violate the existing constraint or if the constraint applies only to the data already in the database.

In This Topic

• Before you begin:

  Limitations and Restrictions

  Security

• To disable a foreign key constraint for INSERT and UPDATE statements, using:

  SQL Server Management Studio

  Transact-SQL

Before You Begin

Limitations and Restrictions

After you disable these constraints, future inserts or updates to the column will not be validated against the constraint conditions.

Security

Permissions

Requires ALTER permission on the table.

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Using SQL Server Management Studio

To disable a foreign key constraint for INSERT and UPDATE statements

1. In Object Explorer, expand the table with the constraint and then expand the Keys folder.

2. Right-click the constraint and select Modify.

3. In the grid under Table Designer, click Enforce Foreign Key Constraint and select No from the drop-down menu.

4. Click Close.

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Using Transact-SQL

To disable a foreign key constraint for INSERT and UPDATE statements

1. In Object Explorer, connect to an instance of Database Engine.

2. On the Standard bar, click New Query.

3. Copy and paste the following examples into the query window and click Execute.

   USE AdventureWorks2012;
   GO
   ALTER TABLE Purchasing.PurchaseOrderHeader
   NOCHECK CONSTRAINT FK_PurchaseOrderHeader_Employee_EmployeeID;
   GO
   

For more information, see ALTER TABLE (Transact-SQL).

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