Compare 2 columns value in a table and show the matching values in a new column . column values are comma seperated - sql

Question

Here I want to compare the comma-separated values from the column roles and userroles, then show the matching values in another column.
I found an example compare comma separated values in sql and used the cursor to iterate rows one by one. it's working for me. but I feel there should be a better way to do it.
Any help is much appreciated.
Create table #temp4
(
user_id int,
permission_id int,
roles varchar(max),
userroles varchar(max),
matchingrolesinthisrow varchar(max))
Insert Into #temp4 values
( 1, -12010, '2341,8760,3546', '1000,1001,1002,1003', null),
( 1, -334, '1002,1001,3467', '2341,1002,3467', null),
( 2, -12349, '9876,9982,6548', '1001,1002,2341', null)
below is the result table I am looking for.
user_id
permission_id
roles
userroles
matchingrolesinthisrow
1
-12010
2341,8760,3546
1000,1001,1002,1003
1
-334
1002,1001,3467
2341,1002,3467
1002,3467
2
-12349
9876,9982,6548
1001,1002,2341
My attempt so far and it's working. please guide me to do this in a better way.
DECLARE #user_id INT
DECLARE #permission_id INT
DECLARE #roles VARCHAR(MAX)
DECLARE #userroles VARCHAR(MAX)
DECLARE #matchingrolesinthisrow VARCHAR(MAX)
declare cur CURSOR LOCAL for
select user_id, permission_id, roles, userroles, matchingrolesinthisrow from #temp4 order by 1
open cur
fetch next from cur into #user_id, #permission_id, #roles, #userroles, #matchingrolesinthisrow
while ##FETCH_STATUS = 0 BEGIN
print (#roles)
print(#userroles)
--execute on each row
UPDATE #temp4
SET matchingrolesinthisrow = T1.[Item]
FROM [developers].[Split](#roles, ',') AS T1
INNER JOIN [developers].[Split](#userroles, ',') AS T2 on T1.[Item] = T2.[Item]
Where roles = #roles and userroles = #userroles and permission_id = #permission_id and user_id = #user_id
fetch next from cur into #user_id, #permission_id, #roles, #userroles, #matchingrolesinthisrow
END
close cur
deallocate cur
--Split function
CREATE FUNCTION [developers].[Split]
(
#s VARCHAR(max),
#split CHAR(1)
)
RETURNS #temptable TABLE ([Item] VARCHAR(MAX))
AS
BEGIN
DECLARE #x XML
SELECT #x = CONVERT(xml,'<root><s>' + REPLACE(#s,#split,'</s><s>') + '</s></root>');
INSERT INTO #temptable
SELECT [Value] = T.c.value('.','varchar(20)')
FROM #X.nodes('/root/s') T(c);
RETURN
END;

Answer 1

Ideally, you should store each inidividual piece of information in separate row, so you should have two separate tables roles and userroles which are foreign-keyed on this one.
Be that as it may, this does not need cursors. You can use STRING_SPLIT and STRING_AGG to get the result you want very easily:
SELECT
t4.user_id,
t4.permission_id,
t4.roles,
t4.userroles,
matchingrolesinthisrow = (
SELECT STRING_AGG(r.value, ',')
FROM STRING_SPLIT(t4.roles, ',') r
JOIN STRING_SPLIT(t4.userroles, ',') ur ON ur.value = r.value
)
FROM #temp4 t4;
SQL Fiddle
If you are on an early version of SQL Server, you will have to use custom Table Valued Functions to do this.

Answer 2

Modified the shared answer to work in the lower version of SQL Server.
SELECT
t4.user_id,
t4.permission_id,
t4.roles,
t4.userroles,
STUFF((SELECT N',' + CONVERT(nvarchar(2000),r.value)
FROM STRING_SPLIT(t4.roles, ',') r
INNER JOIN STRING_SPLIT(t4.userroles, ',') ur ON ur.value = r.value
FOR XML PATH(N''), TYPE).value(N'.[1]', N'nvarchar(max)'), 1, 1, N'') as matchingrolesinthisrow
FROM #temp4 t4;