Check Constraints

A check constraint specifies the data values or formats that are acceptable in one or more columns in a table. For example, you can require the zip column of the authors table to allow only five-digit numeric entries.

You can define many check constraints for a table. You use the Tables property pages to create, modify, or delete each check constraint.

To	See
Attach a check constraint to a table to specify the data values that are acceptable in one or more columns	Attaching a New Check Constraint to a Table or Column
Create a constraint expression to check data for a condition	Defining a Check Constraint Expression
Change the constraint expression or the options that enable or disable the constraint for specific conditions	Modifying a Check Constraint
Apply constraints either to new data only or to existing data as well	Checking Existing Data When Creating a Check Constraint
Disable a check constraint when data is added to, updated in, or deleted from a table	Disabling a Check Constraint with INSERT and UPDATE Statements
Disable a check constraint when your table is replicated in another database	Disabling a Check Constraint for Replication
Remove the limitations on data values in a column	Deleting a Check Constraint