Developers modify a check constraint when they want to change the constraint expression or the options that enable or disable the constraint for specific conditions. When Developers working with SQL Server “Denali”, MS SQL Server 2008 R2 and MS SQL Server 2005 want to modify a check constraint, they should follow the next steps:

1. In their database diagram, right-click the table containing the constraint, then select Properties from the shortcut menu.


Open the Table Designer for the table containing the constraint, right-click in the Table Designer, and choose Check Constraints from the shortcut menu.

2. Choose the Check Constraints tab.

3. Select the constraint they want to change from the Selected Check Constraint list.

4. Complete an action from the following table:

Action to be completed

Steps to be followed

Edit the constraint expression

Type the new expression in the Expression field.

Rename the constraint

Type a new name in the Name field.

Apply the constraint to existing data

Select the Check Existing Data on Creation or Enabling option.

Disable the constraint when new data is added to the table or when existing data is updated in the table.

Clear the Enforce Constraint for INSERTs and UPDATEs option.


Disable the constraint when a replication agent inserts or updates data in their table

Clear the Enforce For Replication option.



The constraint is updated in the database when developers save their table or diagram.