Execute Stored Procedure for List of Parameters in SQL - sql

Question

I have an Stored Procedure that have an argument named Id:
CREATE PROCEDURE [TargetSp](
#Id [bigint]
)
AS
BEGIN
Update [ATable]
SET [AColumn] =
(
Select [ACalculatedValue] From [AnotherTable]
)
Where [ATable].[Member_Id] = #Id
END
So I need to use it for a list of Id's not for one Id like :
Exec [TargetSp]
#Id IN (Select [M].[Id] From [Member] AS [M] Where [M].[Title] = 'Example');
First: How can I Execute it for a list?
Second: Is there any Performance difference between I execute the sp many times or rewrite it in target script?

Answer 1

You could use a table-valued parameter (see http://msdn.microsoft.com/en-us/library/bb510489.aspx). Generally, if you send only one request to the server instead of a list of requests you will see a shorter execution time.

Answer 2

I normally pass in the information like that as XML, then you can use it just like it's a table... selecting, inserting, updating as necessary
DECLARE #IDS NVARCHAR(MAX), #IDOC INT
SET #IDS = N'<ROOT><ID>1</ID><ID>2<ID></ROOT>'
EXEC sp_xml_preparedocument #IDOC OUTPUT, #IDS
SELECT [ID] FROM OPENXML (#IDOC, '/ROOT/ID', 2) WITH ([ID] INT '.') AS XMLDOC
EXEC sp_xml_removedocument #IDOC

Answer 3

Similar to freefaller's example, but using xml type instead and inserting into a table variable #ParsedIds
DECLARE #IdXml XML = N'<root><id value="1"/><id value="2"/></root>'
DECLARE #ParsedIds TABLE (parsedId int not null)
INSERT INTO #ParsedIds (parsedId)
SELECT v.parsedId.value('#value', 'int')
FROM #IdXml.nodes('/root/id') as v(parsedId)
SELECT * FROM #ParsedIds
Interestingly I've worked on an large scale system with 1000's of users and we found that using this method out performed the table-valued parameter approach for small lists of id's (no more than say 5 id's). The table-valued parameter approach was faster for larger lists of Id's.
EDIT following edited question:
Looking at your example it looks like you want to update ATable based on the Title parameter. If you can you'd benefit from rewriting your stored procedure to instead except the title parameter.
create procedure [TargetSP](
#title varchar(50)
)
as
begin
update [ATable]
set [AColumn] =
(
select [ACalculatedValue] from [AnotherTable]
)
where [ATable].[Member_Id] in (select [M].[Id] from [Member] as [M] where [M].[Title] = #title);
end

Answer 4

Since you only care about all the rows with a title of 'Example', you shouldn't need to determine the list first and then tell SQL Server the list you want to update, since you can already identify those with a query. So why not do this instead (I'm guessing at some data types here):
ALTER PROCEDURE dbo.TargetSP
#title VARCHAR(255)
AS
BEGIN
SET NOCOUNT ON;
-- only do this once instead of as a subquery:
DECLARE #v VARCHAR(255) = (SELECT [ACalculatedValue] From [AnotherTable]);
UPDATE a
SET AColumn = #v
FROM dbo.ATable AS a
INNER JOIN dbo.Member AS m
ON a.Member_Id = m.Id
WHERE m.Title = #title;
END
GO
Now call it as:
EXEC dbo.TargetSP #title = 'Example';

Answer 5

DECLARE #VId BIGINT;
DECLARE [My_Cursor] CURSOR FAST_FORWARD READ_ONLY FOR
Select [M].[Id] From [Member] AS [M] Where [M].[Title] = 'Example'
OPEN [My_Cursor]
FETCH NEXT FROM [My_Cursor] INTO #VId
WHILE ##FETCH_STATUS = 0
BEGIN
EXEC [TargetSp]
#Id = #VId
FETCH NEXT FROM [My_Cursor] INTO #VId
END
CLOSE [My_Cursor]
DEALLOCATE [My_Cursor];
GO

Answer 6

if the parameter is integer, you can only pass one value at a time.
Your options are:
call the proc several times, one for each parameter
Change the proc to accept a structure where you can pass more than
one id like a varchar where you pass a coma separated list of values
(not so good) or a table-value parameter
About the performance question, it would be faster to re-write the proc to iterate through a list of ids than call it several times, once per id, BUT unless you are dealing with a HUGE list of ids, I dont think you will see much of a difference