DROP RULE (Transact-SQL)

schema_name

Is the name of the schema to which the rule belongs.

rule

Is the rule to be removed. Rule names must comply with the rules for identifiers. For more information about rules for identifiers, see Using Identifiers As Object Names. Specifying the rule schema name is optional.

To drop a rule, first unbind it if the rule is currently bound to a column or to an alias data type. To unbind the rule, use sp_unbindrule. If the rule is bound when you try to drop it, an error message is displayed and the DROP RULE statement is canceled.

After a rule is dropped, new data entered into the columns previously governed by the rule is entered without the constraints of the rule. Existing data is not affected in any way.

The DROP RULE statement does not apply to CHECK constraints. For more information about dropping CHECK constraints, see ALTER TABLE (Transact-SQL).

To execute DROP RULE, at a minimum, a user must have ALTER permission on the schema to which the rule belongs.

The following example unbinds and then drops the rule named VendorID_rule.

USE AdventureWorks;
GO
IF EXISTS (SELECT name FROM sysobjects
         WHERE name = 'VendorID_rule'
            AND type = 'R')
   BEGIN
      EXEC sp_unbindrule 'Production.ProductVendor.VendorID'
      DROP RULE VendorID_rule
   END
GO

Reference