在sqlserver中查询注释的函数

create function [dbo].[fun_getNotes](@tableName VARCHAR(50),@fieldName VARCHAR(50))
returns varchar(100)
as 
BEGIN
DECLARE @note VARCHAR(100)
select @note=(SELECT TOP 1 cast((SELECT VALUE FROMsys.extended_properties AS ex WHEREex.major_id = c.object_id AND ex.minor_id = c.column_id) as varchar(100)) notes
FROM sys.columns AS c
INNER JOIN sys.tables AS ta ON c.object_id = ta.object_id
INNER JOIN (SELECT name,system_type_id FROM sys.types WHEREname <> 'sysname') AS t ON c.system_type_id = t.system_type_id
              --表名                   字段名
WHERE ta.name = @tableName and c.name= @fieldName)   
  
    RETURN @note 
end;