SQL Server/T-SQL Tutorial/Constraints/Create Rule

Define Rules

The Transact-SQL statement: CREATE RULE rule AS condition
6>
7>
8> CREATE TYPE zip
9>    FROM CHAR(5) NOT NULL
10> GO
1>
2>
3> CREATE RULE zip_rule
4>         AS @number > 600 and @number < 99951
5> GO
1> EXEC sp_bindrule zip_rule, "zip"
2> GO
Rule bound to data type.
The new rule has been bound to column(s) of the specified user data type.
1>
2> CREATE TABLE address
3>         (city CHAR(25) NOT NULL,
4>         zip_code ZIP,
5>         street CHAR(30) NULL)
6> GO
1>
2>
3> drop table address;
4> GO
1>
2> drop rule zip_rule;
3> GO
Msg 3716, Level 16, State 1, Server J\SQLEXPRESS, Line 2
The rule "zip_rule" cannot be dropped because it is bound to one or more type.
1> drop type zip;
2> GO
1>

EXEC sp_helptext on Rules

8>    CREATE RULE SalaryRule
9>       AS @Salary > 0
10> GO
1>    EXEC sp_helptext SalaryRule
2> GO
Text
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
-------------------------------------------------------