sp_updateextendedproperty (Transact-SQL)

[ @name= ]{ 'property_name'}

Is the name of the property to be updated. property_name is sysname, and cannot be NULL.

[ @value= ]{ 'value'}

Is the value associated with the property. value is sql_variant, with a default of NULL. The size of value may not be more than 7,500 bytes.

[ @level0type= ]{ 'level0_object_type'}

Is the user or user-defined type. level0_object_type is varchar(128), with a default of NULL. Valid inputs are ASSEMBLY, CONTRACT, EVENT NOTIFICATION, FILEGROUP, MESSAGE TYPE, PARTITION FUNCTION, PARTITION SCHEME, REMOTE SERVICE BINDING, ROUTE, SCHEMA, SERVICE, USER, TRIGGER, TYPE, and NULL.

Important
USER and TYPE as level-0 types will be removed in a future version of SQL Server. Avoid using these features in new development work, and plan to modify applications that currently use these features. Use SCHEMA as the level 0 type instead of USER. For TYPE, use SCHEMA as the level 0 type and TYPE as the level 1 type.

[ @level0name= ]{ 'level0_object_name'}

Is the name of the level 1 object type specified. level0_object_name is sysname with a default of NULL.

[ @level1type= ]{ 'level1_object_type'}

Is the type of level 1 object. level1_object_type is varchar(128) with a default of NULL. Valid inputs are AGGREGATE, DEFAULT, FUNCTION, LOGICAL FILE NAME, PROCEDURE, QUEUE, RULE, SYNONYM, TABLE, TYPE, VIEW, XML SCHEMA COLLECTION, and NULL.

[ @level1name= ]{ 'level1_object_name'}

Is the name of the level 1 object type specified. level1_object_name is sysname with a default of NULL.

[ @level2type= ]{ 'level2_object_type'}

Is the type of level 2 object. level2_object_type is varchar(128) with a default of NULL. Valid inputs are COLUMN, CONSTRAINT, EVENT NOTIFICATION, INDEX, PARAMETER, TRIGGER, and NULL.

[ @level2name= ]{ 'level2_object_name'}

Is the name of the level 2 object type specified. level2_object_name is sysname, with a default of NULL.

0 (success) or 1 (failure)

For the purpose of specifying extended properties, the objects in a SQL Server database are classified into three levels (0, 1, and 2). Level 0 is the highest level and is defined as objects contained at the database scope. Level 1 objects are contained in a schema or user scope, and level 2 objects are contained by level 1 objects. Extended properties can be defined for objects at any of these levels. References to an object in one level must be qualified with the names of the higher level objects that own or contain them.

Given a valid property_name and value, if all object types and names are null, the property updated belongs to the current database.

Members of the db_owner and db_ddladmin fixed database roles may update the extended properties of any object with the following exception: db_ddladmin may not add properties to the database itself, or to users or roles.

Users may update extended properties to objects they own, or on which they have ALTER or CONTROL permissions.

A. Updating an extended property on a column

USE AdventureWorks2012;
GO
CREATE TABLE T1 (id int , name char (20));
GO
EXEC sp_addextendedproperty 
    @name = N'Caption'
    ,@value = N'Employee ID'
    ,@level0type = N'Schema', @level0name = dbo
    ,@level1type = N'Table',  @level1name = T1
    ,@level2type = N'Column', @level2name = id;
GO
--Update the extended property.
EXEC sp_updateextendedproperty 
    @name = N'Caption'
    ,@value = 'Employee ID must be unique.'
    ,@level0type = N'Schema', @level0name = dbo
    ,@level1type = N'Table',  @level1name = T1
    ,@level2type = N'Column', @level2name = id;
GO

B. Updating an extended property on a database

USE AdventureWorks2012;
GO
EXEC sp_addextendedproperty 
@name = N'NewCaption', @value = 'AdventureWorks2012 Sample OLTP Database';
GO
USE AdventureWorks2012;
GO
EXEC sp_updateextendedproperty 
@name = N'NewCaption', @value = 'AdventureWorks2012 Sample Database';
GO

Reference