Mark nocheck for a constraint : Check « Constraints « SQL Server / T-SQL Tutorial

4>    CREATE TABLE Customers
5>    (
6>       CustomerNo     int     IDENTITY   NOT NULL
7>          PRIMARY KEY,
8>       CustomerName   varchar(30)        NOT NULL,
9>       Address1       varchar(30)        NOT NULL,
10>       Address2       varchar(30)        NOT NULL,
11>      City            varchar(20)        NOT NULL,
12>      State           char(2)            NOT NULL,
13>      Zip             varchar(10)        NOT NULL,
14>      Contact         varchar(25)        NOT NULL,
15>      Phone           char(15)           NOT NULL,
16>      FedIDNo         varchar(9)         NOT NULL,
17>      DateInSystem    smalldatetime      NOT NULL
18>    )
19>    GO
1>    ALTER TABLE Customers
2>       WITH NOCHECK
3>       ADD CONSTRAINT CN_CustomerPhoneNo
4>       CHECK
5>       (Phone LIKE '([0-9][0-9][0-9]) [0-9][0-9][0-9]-[0-9][0-9][0-9][0-9]')
6> go
1>
2>     ALTER TABLE Customers
3>        NOCHECK
4>        CONSTRAINT CN_CustomerPhoneNo
5>
6> GO
1>
2> drop table Customers;
3> GO
1>

7.5.Check
	7.5.1.	Using CHECK Constraints
	7.5.2.	Adding a CHECK Constraint to an Existing Table
	7.5.3.	Constraints with name
	7.5.4.	CHECK Clause
	7.5.5.	Check Constraint
	7.5.6.	CHECK (DATEPART(DAY, GETDATE()) < 28)
	7.5.7.	A check constraint uses an expression to qualify records that are acceptable for any Inserts or Updates
	7.5.8.	Use or to link two conditions for check constraint
	7.5.9.	Using a Multicolumn CHECK Constraint
	7.5.10.	Check for data length
	7.5.11.	Pattern based constraint
	7.5.12.	Mark nocheck for a constraint
	7.5.13.	A table-level check constraint that limits Banker IDs to a specific format