Stored Procedure with multi value parameter behaving strangely - sql

Question

I created a stored procedure in sql server to feed SSRS to allow it to accept Multiple values.
I have created it and when I used it in my report or execute it in sql server I have the following error message. Is there anything i am missing? Thanks
Msg 207, Level 16, State 1, Line 35
Invalid column name 'London'.
This is my sample data. feel free to create table with it
DECLARE #MyTables AS TABLE (ID INT, City VARCHAR(100))
INSERT INTO #MyTables VALUES
(1,'London'),
(2,'Chester'),
(3,'Luton'),
(4,'New York'),
(1,'London'),
(2,'Chester'),
(5,'Paris'),
(5,'Paris'),
(2,'Chester'),
(2,'Chester')
SELECT * FROM #MyTables
This is my code for the dynamic stores procedure
CREATE PROCEDURE dbo.CitiesGroup
#Cities NVARCHAR(Max) -- this are the parameters
AS
BEGIN
DECLARE #sqLQuery VARCHAR(MAX)
Declare #AnswersTempTable Table
( ID INT,
City VARCHAR(250)
)
SET #sqlQuery =
'SELECT
ID,
City
FROM MyTables
where Convert(nvarchar(Max),City) IN ('+#Cities+')
Insert into #AnswersTempTable
exec (#sqlQuery)
select * from #AnswersTempTable'
END
Thanks
EXEC dbo.CitiesGroup 'London'
Error meg
Msg 207, Level 16, State 1, Line 32
Invalid column name 'London'.

Answer 1

There is another way to do this. Instead of passing the values into a dynamic query, why not split the parameter using a function? This article written by Aaron Bertrand demonstrates different ways on how to split string in sql server.
Once you have selected one of the functions, you can simply rewrite your stored procedure without creating a dynamic query inside.
CREATE PROCEDURE dbo.CitiesGroup
#Cities NVARCHAR(Max) -- this are the parameters
AS
BEGIN
-- simplified query
-- write your complex logic here
SELECT ID, City
FROM MyTables
WHERE City IN (SELECT Item FROM dbo.SplitStrings_CTE(#Cities, N',');)
END
Usage:
EXEC dbo.CitiesGroup 'London'
GO
EXEC dbo.CitiesGroup 'London,New York,Paris'
GO
Useful Link:
Split strings the right way – or the next best way

Answer 2

Alternatively, if you don't need to use a stored proc, you can simply put your query directly in the dataset as
SELECT ID, City
FROM MyTables
WHERE City IN (#Cities)
There is no need for dynamic sql as SSRS will do this for you. Just makes sure the SSRS parameter name and the Variable in your SELECT statement are identical (case-sensitive)