Delete a check constraint when you want to remove the limitations on data values that are accepted in the column or columns included in the constraint expression.
Note Some databases have different functionality for check constraints. For more information about the differences between databases, see Database Server Considerations. Consult your database documentation for details about how your database works with check constraints.
To delete a check constraint
Caution Choosing Delete will result in an action that cannot be undone without losing all other changes made to the database diagram. To undo this action, close this database diagram and all other open database diagrams without saving the changes.
The constraint is deleted from the database when you save the table or diagram.