是否有解决方案来获取给定存储过程的参数的默认值？

Question

我INFORMATION_SCHEMA.PARAMETERS现在用于获取有关存储过程参数的信息。我需要知道参数的默认值。是否有解决方案来获取给定存储过程的参数的默认值？

Answer 1

如果您通过 SQL 命令执行此操作，请解析 SQL 代码...

该信息不存储在系统表中。从sys.parameters（您期望的位置）、has_default_value 和 default_value 列，我们被告知解析 SQL：

SQL Server 仅维护此目录视图中 CLR 对象的默认值；因此，对于 Transact-SQL 对象，此列的值为 0。若要查看 Transact-SQL 对象中参数的默认值，请查询 sys.sql_modules 目录视图的定义列，或使用 OBJECT_DEFINITION 系统函数。

如果 has_default_value 为 1，则该列的值为该参数的默认值；否则为 NULL。

证明：

CREATE PROC dbo.Paramtest (@foo int = 42)
AS
SET NOCOUNT ON;
GO

SELECT OBJECT_NAME(object_id), has_default_value, default_value
FROM sys.parameters
WHERE name = '@foo' AND object_id = OBJECT_ID('dbo.Paramtest')

-- gives Paramtest, 0, NULL

Answer 2

Declare @pSProcName NVARCHAR(MAX)='ProcedureName'

DECLARE @SQLTEXT NVARCHAR(MAX),@start int ,@end int,@SearchCode NVARCHAR(MAX)
SELECT @SQLTEXT =OBJECT_DEFINITION(OBJECT_ID(@pSProcName))
SELECT @start=CHARINDEX('@',@SQLTEXT,1)
SELECT @end =min(val) FROM (
SELECT PATINDEX('%'+CHAR(10)+'AS'+CHAR(10)+'%',@SQLTEXT ) AS val
UNION ALL SELECT PATINDEX('%'+CHAR(10)+'AS'+CHAR(13)+'%',@SQLTEXT )
UNION ALL SELECT PATINDEX('%'+CHAR(13)+'AS'+CHAR(10)+'%',@SQLTEXT )
UNION ALL SELECT PATINDEX('%'+CHAR(13)+'AS'+CHAR(13)+'%',@SQLTEXT )
UNION ALL SELECT PATINDEX('%'+CHAR(10)+'AS'+CHAR(32)+'%',@SQLTEXT )
UNION ALL SELECT PATINDEX('%'+CHAR(32)+'AS'+CHAR(10)+'%',@SQLTEXT )
UNION ALL SELECT PATINDEX('%'+CHAR(32)+'AS'+CHAR(32)+'%',@SQLTEXT )
UNION ALL SELECT PATINDEX('%'+CHAR(13)+'AS'+CHAR(32)+'%',@SQLTEXT )
UNION ALL SELECT PATINDEX('%'+CHAR(32)+'AS'+CHAR(13)+'%',@SQLTEXT )
) S 
Where s.val <> 0

SELECT @SearchCode=SUBSTRING(@sqltext,@start,@end - @start)
SELECT S2.parameter_id,S2.ParameterName,S2.DataType,S1.Default_Value FROM
(
SELECT CASE WHEN Data like '%=%' then RIGHT(Data,len(Data)-CHARINDEX('=',Data,1)) ELSE '' END as Default_Value, 
CASE WHEN Data like '%=%' then 1 ELSE 0 END as Has_default_Value
,Data FROM(
SELECT LTRIM(RTRIM(Split.a.value('.', 'VARCHAR(100)'))) AS Data  
 FROM  
 (
     SELECT  CAST ('<M>' + REPLACE(@SearchCode, ',', '</M><M>') + '</M>' AS XML) AS Data  

 ) AS A CROSS APPLY Data.nodes ('/M') AS Split(a))s
 )S1 

INNER JOIN
(
Select p.parameter_id,p.name as ParameterName,UPPER(t.name) AS DataType from sys.all_parameters p
Inner JOIN sys.types t
on t.user_type_id = p.user_type_id
where Object_name(OBJECT_ID) = @pSProcName
) S2
ON S1.Data LIKE '%'+S2.ParameterName+'%'+S2.DataType+'%'