SQL - Lookup multiple values from same field - sql

Question

Issue and desired result explained in SQL code below. I had a partially working solution using a cursor and while loop sub-statement but was still struggling with the fact that there can be any number of userIds in the same field (0-10 for instance) and some of the userids may not even have a valid match in the lookup table.
Example data source table. We need to find the user names based on the user ids
drop table #sourcetable
Create table #sourcetable (rowid int
,userId varchar(50))
Insert #sourcetable
Values ('1','123456789')
Insert #sourcetable
Values ('2','123456789'+','+'456821495')
Insert #sourcetable
Values ('3','123456789'+','+'456821495'+','+'589642304')
Example lookup table. We have a table with all users listed by user id
drop table #lookuptable
Create table #lookuptable (userId varchar(50)
,Username varchar(100))
Insert #lookuptable
Values ('123456789','User A')
Insert #lookuptable
Values ('456821495','User B')
Insert #lookuptable
Values ('589642304','User C')
This is the expected result. The issue is that there can be multiple (any number) userids in the 1 userid field in the source table. The only constant factors are that valid userids will always be 9 digits and each will be seperate by ',' if there are multiple IDs in the field. (SQL v2008 server)
drop table #Resulttable
Create table #Resulttable (rowid int
,userId varchar(50)
,Username varchar(100))
Insert #Resulttable
Values ('1','123456789','User A')
Insert #Resulttable
Values ('2','123456789'+','+'456821495','User A,User B')
Insert #Resulttable
Values ('3','123456789'+','+'456821495'+','+'589642304','User A,User B,User C')
select *
from #lookuptable
select *
from #sourcetable
select *
from #Resulttable

Answer 1

I recommend to change the way your data is stored. SQL Server is not optimized to have multiple values in a single field. If you can't change the way the data is stored, here is a way you can get your desired results(I cleaned up your code a bit).
IF OBJECT_ID('tempdb..#sourcetable') IS NOT NULL
DROP TABLE #sourceTable
CREATE TABLE #sourcetable (
rowid INT,
userId VARCHAR(50)
);
INSERT INTO #sourcetable
VALUES ('1','123456789'),
('2','123456789'+','+'456821495'),
('3','123456789'+','+'456821495'+','+'589642304');
IF OBJECT_ID('tempdb..#lookuptable') IS NOT NULL
DROP TABLE #lookupTable;
CREATE TABLE #lookuptable (
userId varchar(50),
Username varchar(100)
);
INSERT INTO #lookuptable
VALUES ('123456789','User A'),
('456821495','User B'),
('589642304','User C');
IF OBJECT_ID('tempdb..#ResultTable') IS NOT NULL
DROP TABLE #ResultTable
CREATE TABLE #Resulttable ( rowid INT,
userId VARCHAR(50),
Username VARCHAR(100)
);
INSERT INTO #Resulttable
VALUES ('1','123456789','User A'),
('2','123456789'+','+'456821495','User A,User B'),
('3','123456789'+','+'456821495'+','+'589642304','User A,User B,User C');
WITH CTE_Results
AS
(
select B.rowID,
B.userId,
A.Username
from #lookuptable A
LEFT JOIN #sourcetable B
ON CAST(B.userId AS VARCHAR(100)) LIKE '%' + CAST(A.userId AS VARCHAR(10)) + '%'
)
SELECT rowid,
userId,
STUFF((
SELECT ',' + Username
FROM CTE_Results A
WHERE (A.userId = B.UserID)
ORDER BY Username
FOR XML PATH(''),TYPE).value('(./text())[1]','VARCHAR(MAX)')
,1,1,'') AS Usernames
FROM CTE_Results B
GROUP BY rowid, userId;
Results:
rowid userId Usernames
----------- ----------------------------- -----------------------
1 123456789 User A
2 123456789,456821495 User A,User B
3 123456789,456821495,589642304 User A,User B,User C

Answer 2

I only can agree with BDL: You should not store your data like that.
But sometimes you have no choice so here a working solution.
What you need to do is to split up your userIds first, then join, and then concatenate your Usernames again. This would then look like:
insert into #Resulttable (rowid, userId, Username)
select rowid, userId
, stuff(
(select ',' + l.Username
from #sourcetable as s
cross apply dbo.udf_SplitWordList(s.userId,',') as split
join #lookuptable as l
on l.userId = split.Word
where s.rowid = s_out.rowid
for XML PATH(''), type).value('(./text())[1]','nvarchar(max)')
, 1, 1, '') Username
from #sourcetable as s_out
You can replace my splitting function [dbo].[udf_SplitWordList] with your preferred one.
If you haven't one yet, this is the one I use
-- =============================================
-- Description: This function can split up a sting by a given delimiter
-- Limitations: Currently the maximum input string length is 983,040. To process longer strings, the function has to be adjusted.
-- USAGE:
/*
SELECT * FROM dbo.udf_SplitWordList('Hello,World',',') -- Separater = ,
SELECT * FROM dbo.udf_SplitWordList('Hello|World','|') -- Separater = ,
SELECT * FROM dbo.udf_SplitWordList('HelloWorld',CHAR(127)) -- Separater = DEL
SELECT * FROM dbo.udf_SplitWordList('HelloWorld',CHAR(27)) -- Separater = ESC
*/
-- =============================================
CREATE FUNCTION [dbo].[udf_SplitWordList]
(
#list NVARCHAR(MAX)
, #delimiter NVARCHAR(10)
)
RETURNS #t TABLE
(
Word NVARCHAR(MAX) NOT NULL,
Position INT IDENTITY(1,1) NOT NULL
)
AS
BEGIN
DECLARE #list_len BIGINT, #del_len INT
SET #list_len = LEN(#list)
SET #del_len = LEN(REPLACE(#delimiter,' ','_'))
IF #list_len < 16
INSERT #t
SELECT SUBSTRING(#delimiter + #List + #delimiter, w.i + #del_len, CHARINDEX(#delimiter, #delimiter + #List + #delimiter, w.i + #del_len) - w.i - #del_len) value
FROM (
SELECT v0.n i
FROM (SELECT 0 n UNION ALL SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3 UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL SELECT 6 UNION ALL SELECT 7 UNION SELECT 8 UNION ALL SELECT 9 UNION ALL SELECT 10 UNION ALL SELECT 11 UNION ALL SELECT 12 UNION ALL SELECT 13 UNION ALL SELECT 14 UNION ALL SELECT 15) v0
) w
WHERE w.i = CHARINDEX(#delimiter, #delimiter + #List + #delimiter, w.i) AND w.i < #list_len + #del_len
ORDER BY i
ELSE IF #list_len < 256
INSERT #t
SELECT SUBSTRING(#delimiter + #List + #delimiter, w.i + #del_len, CHARINDEX(#delimiter, #delimiter + #List + #delimiter, w.i + #del_len) - w.i - #del_len) value
FROM (
SELECT v0.n + v1.n i
FROM (SELECT 0 n UNION ALL SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3 UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL SELECT 6 UNION ALL SELECT 7 UNION SELECT 8 UNION ALL SELECT 9 UNION ALL SELECT 10 UNION ALL SELECT 11 UNION ALL SELECT 12 UNION ALL SELECT 13 UNION ALL SELECT 14 UNION ALL SELECT 15) v0
, (SELECT 0 n UNION ALL SELECT 16 UNION ALL SELECT 32 UNION ALL SELECT 48 UNION ALL SELECT 64 UNION ALL SELECT 80 UNION ALL SELECT 96 UNION ALL SELECT 112 UNION SELECT 128 UNION ALL SELECT 144 UNION ALL SELECT 160 UNION ALL SELECT 176 UNION ALL SELECT 192 UNION ALL SELECT 208 UNION ALL SELECT 224 UNION ALL SELECT 240) v1
) w
WHERE w.i = CHARINDEX(#delimiter, #delimiter + #List + #delimiter, w.i) AND w.i < #list_len + #del_len
ORDER BY i
ELSE IF #list_len < 4096
INSERT #t
SELECT SUBSTRING(#delimiter + #List + #delimiter, w.i + #del_len, CHARINDEX(#delimiter, #delimiter + #List + #delimiter, w.i + #del_len) - w.i - #del_len) value
FROM (
SELECT v0.n + v1.n + v2.n i
FROM (SELECT 0 n UNION ALL SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3 UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL SELECT 6 UNION ALL SELECT 7 UNION SELECT 8 UNION ALL SELECT 9 UNION ALL SELECT 10 UNION ALL SELECT 11 UNION ALL SELECT 12 UNION ALL SELECT 13 UNION ALL SELECT 14 UNION ALL SELECT 15) v0
, (SELECT 0 n UNION ALL SELECT 16 UNION ALL SELECT 32 UNION ALL SELECT 48 UNION ALL SELECT 64 UNION ALL SELECT 80 UNION ALL SELECT 96 UNION ALL SELECT 112 UNION SELECT 128 UNION ALL SELECT 144 UNION ALL SELECT 160 UNION ALL SELECT 176 UNION ALL SELECT 192 UNION ALL SELECT 208 UNION ALL SELECT 224 UNION ALL SELECT 240) v1
, (SELECT 0 n UNION ALL SELECT 256 UNION ALL SELECT 512 UNION ALL SELECT 768 UNION ALL SELECT 1024 UNION ALL SELECT 1280 UNION ALL SELECT 1536 UNION ALL SELECT 1792 UNION SELECT 2048 UNION ALL SELECT 2304 UNION ALL SELECT 2560 UNION ALL SELECT 2816 UNION ALL SELECT 3072 UNION ALL SELECT 3328 UNION ALL SELECT 3584 UNION ALL SELECT 3840) v2
) w
WHERE w.i = CHARINDEX(#delimiter, #delimiter + #List + #delimiter, w.i) AND w.i < #list_len + #del_len
ORDER BY i
ELSE IF #list_len < 65536
INSERT #t
SELECT SUBSTRING(#delimiter + #List + #delimiter, w.i + #del_len, CHARINDEX(#delimiter, #delimiter + #List + #delimiter, w.i + #del_len) - w.i - #del_len) value
FROM (
SELECT v0.n + v1.n + v2.n + v3.n i
FROM (SELECT 0 n UNION ALL SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3 UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL SELECT 6 UNION ALL SELECT 7 UNION SELECT 8 UNION ALL SELECT 9 UNION ALL SELECT 10 UNION ALL SELECT 11 UNION ALL SELECT 12 UNION ALL SELECT 13 UNION ALL SELECT 14 UNION ALL SELECT 15) v0
, (SELECT 0 n UNION ALL SELECT 16 UNION ALL SELECT 32 UNION ALL SELECT 48 UNION ALL SELECT 64 UNION ALL SELECT 80 UNION ALL SELECT 96 UNION ALL SELECT 112 UNION SELECT 128 UNION ALL SELECT 144 UNION ALL SELECT 160 UNION ALL SELECT 176 UNION ALL SELECT 192 UNION ALL SELECT 208 UNION ALL SELECT 224 UNION ALL SELECT 240) v1
, (SELECT 0 n UNION ALL SELECT 256 UNION ALL SELECT 512 UNION ALL SELECT 768 UNION ALL SELECT 1024 UNION ALL SELECT 1280 UNION ALL SELECT 1536 UNION ALL SELECT 1792 UNION SELECT 2048 UNION ALL SELECT 2304 UNION ALL SELECT 2560 UNION ALL SELECT 2816 UNION ALL SELECT 3072 UNION ALL SELECT 3328 UNION ALL SELECT 3584 UNION ALL SELECT 3840) v2
, (SELECT 0 n UNION ALL SELECT 4096 UNION ALL SELECT 8192 UNION ALL SELECT 12288 UNION ALL SELECT 16384 UNION ALL SELECT 20480 UNION ALL SELECT 24576 UNION ALL SELECT 28672 UNION ALL SELECT 32768 UNION ALL SELECT 36864 UNION ALL SELECT 40960 UNION ALL SELECT 45056 UNION ALL SELECT 49152 UNION ALL SELECT 53248 UNION ALL SELECT 57344 UNION ALL SELECT 61440) v3
) w
WHERE w.i = CHARINDEX(#delimiter, #delimiter + #List + #delimiter, w.i) AND w.i < #list_len + #del_len
ORDER BY i
ELSE
INSERT #t
SELECT SUBSTRING(#delimiter + #List + #delimiter, w.i + #del_len, CHARINDEX(#delimiter, #delimiter + #List + #delimiter, w.i + #del_len) - w.i - #del_len) value
FROM (
SELECT v0.n + v1.n + v2.n + v3.n + v4.n i
FROM (SELECT 0 n UNION ALL SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3 UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL SELECT 6 UNION ALL SELECT 7 UNION SELECT 8 UNION ALL SELECT 9 UNION ALL SELECT 10 UNION ALL SELECT 11 UNION ALL SELECT 12 UNION ALL SELECT 13 UNION ALL SELECT 14 UNION ALL SELECT 15) v0
, (SELECT 0 n UNION ALL SELECT 16 UNION ALL SELECT 32 UNION ALL SELECT 48 UNION ALL SELECT 64 UNION ALL SELECT 80 UNION ALL SELECT 96 UNION ALL SELECT 112 UNION SELECT 128 UNION ALL SELECT 144 UNION ALL SELECT 160 UNION ALL SELECT 176 UNION ALL SELECT 192 UNION ALL SELECT 208 UNION ALL SELECT 224 UNION ALL SELECT 240) v1
, (SELECT 0 n UNION ALL SELECT 256 UNION ALL SELECT 512 UNION ALL SELECT 768 UNION ALL SELECT 1024 UNION ALL SELECT 1280 UNION ALL SELECT 1536 UNION ALL SELECT 1792 UNION SELECT 2048 UNION ALL SELECT 2304 UNION ALL SELECT 2560 UNION ALL SELECT 2816 UNION ALL SELECT 3072 UNION ALL SELECT 3328 UNION ALL SELECT 3584 UNION ALL SELECT 3840) v2
, (SELECT 0 n UNION ALL SELECT 4096 UNION ALL SELECT 8192 UNION ALL SELECT 12288 UNION ALL SELECT 16384 UNION ALL SELECT 20480 UNION ALL SELECT 24576 UNION ALL SELECT 28672 UNION ALL SELECT 32768 UNION ALL SELECT 36864 UNION ALL SELECT 40960 UNION ALL SELECT 45056 UNION ALL SELECT 49152 UNION ALL SELECT 53248 UNION ALL SELECT 57344 UNION ALL SELECT 61440) v3
, (SELECT 0 n UNION ALL SELECT 65536 UNION ALL SELECT 131072 UNION ALL SELECT 196608 UNION ALL SELECT 262144 UNION ALL SELECT 327680 UNION ALL SELECT 393216 UNION ALL SELECT 458752 UNION ALL SELECT 524288 UNION ALL SELECT 589824 UNION ALL SELECT 655360 UNION ALL SELECT 720896 UNION ALL SELECT 786432 UNION ALL SELECT 851968 UNION ALL SELECT 917504 UNION ALL SELECT 983040) v4
) w
WHERE w.i = CHARINDEX(#delimiter, #delimiter + #List + #delimiter, w.i) AND w.i < #list_len + #del_len
ORDER BY i
RETURN
END