A fairly comprehensive query of the brain has turned up a thousand and one ways to pass variable length parameter lists that involve such methods as:
- CLR based methods for parsing strings to lists of integers
- Table valued functions that require the presence of a 'Numbers' table (wtf?)
- Passing the data as XML
Our requirements are to pass two variable length lists of integers (~max 20 ints) to a stored procedure. All methods outlined above seem to smell funny.
Is this just the way it has to be done, or is there a better way?
Edit:
I've just found this, which may qualify this question as a dupe
Yes, I'd definitely look at Table Valued Parameters for this. As a side benefit, it may allow you to use a nice, clean set-based implementation for the innards of your procedure directly, without any data massaging required.
Here's another reference as well...
Here is a fairly fast method to split strings using only T-SQL and you input parameter is only a string. You need to have a table and a function (as described below) already set up to use this method.
create this table:
CREATE TABLE Numbers (Number int not null primary key identity(1,1))
DECLARE @n int
SET @n=1
SET IDENTITY_INSERT Numbers ON
WHILE @N<=8000
BEGIN
INSERT INTO Numbers (Number) values (@n)
SET @n=@n+1
END
SET IDENTITY_INSERT Numbers OFF
create this function to split the string array (I have other versions, where empty sections are eliminated and ones that do not return row numbers):
CREATE FUNCTION [dbo].[FN_ListAllToNumberTable]
(
@SplitOn char(1) --REQUIRED, the character to split the @List string on
,@List varchar(8000) --REQUIRED, the list to split apart
)
RETURNS
@ParsedList table
(
RowNumber int --REQUIRED, the list to split apart
,ListValue varchar(500) --OPTIONAL, the character to split the @List string on, defaults to a comma ","
)
AS
BEGIN
--this will return empty rows, and row numbers
INSERT INTO @ParsedList
(RowNumber,ListValue)
SELECT
ROW_NUMBER() OVER(ORDER BY number) AS RowNumber
,LTRIM(RTRIM(SUBSTRING(ListValue, number+1, CHARINDEX(@SplitOn, ListValue, number+1)-number - 1))) AS ListValue
FROM (
SELECT @SplitOn + @List + @SplitOn AS ListValue
) AS InnerQuery
INNER JOIN Numbers n ON n.Number < LEN(InnerQuery.ListValue)
WHERE SUBSTRING(ListValue, number, 1) = @SplitOn
RETURN
END
go
here is an example of how to split the parameter apart:
CREATE PROCEDURE TestPass
(
@ArrayOfInts varchar(255) --pipe "|" separated list of IDs
)
AS
SET NOCOUNT ON
DECLARE @TableIDs TABLE (RowNumber int, IDValue int null)
INSERT INTO @TableIDs (RowNumber, IDValue) SELECT RowNumber,CASE WHEN LEN(ListValue)<1 then NULL ELSE ListValue END FROM dbo.FN_ListAllToNumberTable('|',@ArrayOfInts)
SELECT * FROM @TableIDs
go
this is based on: http://www.sommarskog.se/arrays-in-sql.html