Tip: Pass Comma Separated Values as a Parameter to an SQL Stored Procedure

There will be times when you need to pass a list of values as a singular parameter to an SQL Stored Procedure. Problem is: SQL doesn't support this. You will need to create a separate function to split the input (the supplied) string and then pass it to the desired Stored Procedure.

Listing 1. Create the SQL Function that allows us to split the given parameters nicely:

CREATE FUNCTION Split
(
@InputString NVARCHAR(MAX),
@Delimiter CHAR(1)
)
RETURNS @Result TABLE (
Desired NVARCHAR(1000)
)
AS
BEGIN
DECLARE @Start INT, @End INT

SET @StartIndex = 1
IF SUBSTRING(@InputString, LEN(@InputString) - 1, LEN(@InputString)) <> @Delimiter
BEGIN
SET @InputString = @InputString + @Delimiter
END

WHILE CHARINDEX(@Delimiter, @InputString) > 0
BEGIN
SET @End = CHARINDEX(@Delimiter, @InputString)

INSERT INTO @Result(Desired)
SELECT SUBSTRING(@InputString, @Start, @End - 1)

SET @InputString = SUBSTRING(@InputString, @End + 1, LEN(@InputString))
END

RETURN
END

Listing 2. Create the Stored Procedure that can accept comma separated values as one of its parameters:

CREATE PROCEDURE GetStudents
@StudentIDs VARCHAR(100)
AS
BEGIN
SELECT StudentName, StudentSurname
FROM Students
WHERE StudentID IN(
SELECT CAST(Desired AS INTEGER)
FROM dbo.Split(@StudentIDs, ',')
)
END

In the above Stored Procedure, the Function that formats the result gets called. Finally, Execute the Stored Procedure:

EXEC GetStudents '11234,11239,11568,22136'

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