sp_unbindrule (Transact-SQL)

Unbinds a rule from a column or an alias data type in the current database.


This feature will be removed in the next version of Microsoft SQL Server. Do not use this feature in new development work, and modify applications that currently use this feature as soon as possible. We recommend that you create default definitions by using the DEFAULT keyword in the ALTER TABLE or CREATE TABLE statements instead. For more information, see Creating and Modifying DEFAULT Definitions.

Topic link iconTransact-SQL Syntax Conventions


sp_unbindrule [ @objname= ] 'object_name' 
     [ , [ @futureonly= ] 'futureonly_flag' ]


  • [ **@objname=** ] 'object_name'
    Is the name of the table and column or the alias data type from which the rule is unbound. object_name is nvarchar(776), with no default. SQL Server attempts to resolve two-part identifiers to column names first, then to alias data types. When unbinding a rule from an alias data type, any columns of the data type that have the same rule are also unbound. Columns of that data type with rules bound directly to them are unaffected.


    object_name can contain brackets [] as delimited identifier characters. For more information, see Delimited Identifiers (Database Engine).

  • [ **@futureonly=** ] 'futureonly_flag'
    Is used only when unbinding a rule from an alias data type. futureonly_flag is varchar(15), with a default of NULL. When futureonly_flag is futureonly, existing columns of that data type do not lose the specified rule.

Return Code Values

0 (success) or 1 (failure)


To display the text of a rule, execute sp_helptext with the rule name as the parameter.

When a rule is unbound, the information about the binding is removed from the sys.columns table if the rule was bound to a column, and from the sys.types table if the rule was bound to an alias data type.

When a rule is unbound from an alias data type, it is also unbound from any columns having that alias data type. The rule may also still be bound to columns whose data types were later changed by the ALTER COLUMN clause of an ALTER TABLE statement, you must specifically unbind the rule from these columns by using sp_unbindrule and specifying the column name.


To unbind a rule from a table column requires ALTER permission on the table. To unbind a rule from an alias data type requires CONTROL permission on the type or ALTER permission on the schema to which the type belongs.


A. Unbinding a rule from a column

The following example unbinds the rule from the startdate column of an employees table.

EXEC sp_unbindrule 'employees.startdate'

B. Unbinding a rule from an alias data type

The following example unbinds the rule from the alias data type ssn. It unbinds the rule from existing and future columns of that type.

EXEC sp_unbindrule ssn

C. Using futureonly_flag

The following example unbinds the rule from the alias data type ssn without affecting existing ssn columns.

EXEC sp_unbindrule 'ssn', 'futureonly'

D. Using delimited identifiers

The following example shows using delimited identifiers in the object_name parameter.

CREATE TABLE [t.4] (c1 int) -- Notice the period as part of the table 
-- name.
CREATE RULE rule2 AS @value > 100
EXEC sp_bindrule rule2, '[t.4].c1' -- The object contains two 
-- periods; the first is part of the table name and the second 
-- distinguishes the table name from the column name.
EXEC sp_unbindrule '[t.4].c1'