sp_addextendedproperty  
    [ @name = ] { 'property_name' }  --添加的属性的名称
    [ , [ @value = ] { 'value' }    --与属性关联的值    
    [ , [ @level0type = ] { 'level0_object_type' }  --是级别0对象的类型 
    , [ @level0name = ] { 'level0_object_name' }    --是指定的0级对象类型的名称
    [ , [ @level1type = ] { 'level1_object_type' } --是级别1对象的类型  
    , [ @level1name = ] { 'level1_object_name' }   --是指定的1级对象类型的名称
     [ , [ @level2type = ] { 'level2_object_type' } --是2级对象的类型  
      , [ @level2name = ] { 'level2_object_name' }  --是指定的2级对象类型的名称 
                        ]   
                ]  
        ]   
    ]   
[;]

---将扩展属性添加到表中的列


CREATE TABLE [dbo].[SYS_UserPermissions](
	[ID] [int] PRIMARY KEY NOT NULL,
	[UserID] [int] NOT NULL,
	[xType] [tinyint] NULL,
	[ElementID] [int] NOT NULL,
	[Permission] [smallint] NULL,
	[Modifier] [varchar](20) NULL,
	[ModifyDate] [datetime] NULL,



EXEC sys.sp_addextendedproperty @name=N'MS_Description', @value=N'ID' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'SYS_UserPermissions', @level2type=N'COLUMN',@level2name=N'ID'
GO

EXEC sys.sp_addextendedproperty @name=N'MS_Description', @value=N'角色ID' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'SYS_UserPermissions', @level2type=N'COLUMN',@level2name=N'UserID'
GO

EXEC sys.sp_addextendedproperty @name=N'MS_Description', @value=N'类型' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'SYS_UserPermissions', @level2type=N'COLUMN',@level2name=N'xType'
GO

EXEC sys.sp_addextendedproperty @name=N'MS_Description', @value=N'元素ID' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'SYS_UserPermissions', @level2type=N'COLUMN',@level2name=N'ElementID'
GO

EXEC sys.sp_addextendedproperty @name=N'MS_Description', @value=N'权限' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'SYS_UserPermissions', @level2type=N'COLUMN',@level2name=N'Permission'
GO

EXEC sys.sp_addextendedproperty @name=N'MS_Description', @value=N'用户独立权限表' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'SYS_UserPermissions'
GO