SQL breakup string for use with WHERE IN - sql

Question

I have a table in SQL Server with a column that stores a series of characters. I would like to be able to send a series of characters to a stored procedure and use it for the WHERE IN. Example below
ID | series
---+-------
1 | U
2 | B
3 | R
4 | UB
5 | BR
I would like a return as follows:
Parameter | Return IDs
----------+------------
U | 1
R | 3
U, R | 1, 3
I can format the parameter any way, UR or U, R or whatever. I could break this up in application and call the procedure N times but I would rather not so that I can use an order by in the query.

Answer 1

Here's one way if you can not use a table valued parameter.
declare #table table (ID int, series varchar(16))
insert into #table
values
(1,'U'),
(2,'B'),
(3,'R'),
(4,'UB'),
(5,'BR')
declare #input varchar(4000) = 'U,R'
select
t.*
from #table t
cross apply dbo.DelimitedSplit8K(#input,',') x
where
x.Item = t.series
OR without Cross Apply
;with cte as
(select *
from dbo.DelimitedSplit8K(#input,',') x )
select
t.*
from #table t
inner join cte on Item = t.series
Here is the function which has proven to be a fast method of splitting strings:
CREATE FUNCTION [dbo].[DelimitedSplit8K] (#pString VARCHAR(8000), #pDelimiter CHAR(1))
--WARNING!!! DO NOT USE MAX DATA-TYPES HERE! IT WILL KILL PERFORMANCE!
RETURNS TABLE WITH SCHEMABINDING AS
RETURN
/* "Inline" CTE Driven "Tally Table" produces values from 1 up to 10,000...
enough to cover VARCHAR(8000)*/
WITH E1(N) AS (
SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1 UNION ALL
SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1 UNION ALL
SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1
), --10E+1 or 10 rows
E2(N) AS (SELECT 1 FROM E1 a, E1 b), --10E+2 or 100 rows
E4(N) AS (SELECT 1 FROM E2 a, E2 b), --10E+4 or 10,000 rows max
cteTally(N) AS (--==== This provides the "base" CTE and limits the number of rows right up front
-- for both a performance gain and prevention of accidental "overruns"
SELECT TOP (ISNULL(DATALENGTH(#pString),0)) ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) FROM E4
),
cteStart(N1) AS (--==== This returns N+1 (starting position of each "element" just once for each delimiter)
SELECT 1 UNION ALL
SELECT t.N+1 FROM cteTally t WHERE SUBSTRING(#pString,t.N,1) = #pDelimiter
),
cteLen(N1,L1) AS(--==== Return start and length (for use in substring)
SELECT s.N1,
ISNULL(NULLIF(CHARINDEX(#pDelimiter,#pString,s.N1),0)-s.N1,8000)
FROM cteStart s
)
--===== Do the actual split. The ISNULL/NULLIF combo handles the length for the final element when no delimiter is found.
SELECT ItemNumber = ROW_NUMBER() OVER(ORDER BY l.N1),
Item = SUBSTRING(#pString, l.N1, l.L1)
FROM cteLen l
;
GO

Answer 2

On way to achieve this is to pass in a delimited string and then create a function to take in your parameter, splits out the values and returns a table value. Then all you need to do is create a stored procedure similar to.
CREATE PROCEDURE MyProc
(
#MyParameter NVARCHAR(3000)
)
AS
SELECT
ID,
Series
FROM
MyTable
WHERE
Series IN (SELECT ID FROM dbo.MyFunctionToSplitDelimitedString(#MyParameter,',')