Difference between Check Constraint and Rule

Difference between Check Constraint and Rule

S.No	Check Constraint	Rule
1	Check constraint is associated with columns in a Table. So these cannot be re-used.	Rules are defined with in a database and can be applied to any number of columns

Example for Constraint:

alter table Emp add constraint ck_op Check (Salary between 15000 and 45000)

Example for Rule (Creation & Binding):

Creating Rule:

CREATE RULE SAL_RANGE

as

@Sal > 15000 and @Sal > 45000

Binding Rule to a Column:

SP_BINDRULE 'SAL_RANGE','Emp.Salary'

Summary:

The major difference between rule and Check is re usability