How to split String after CONCAT over the repetition of Row Number - sql

Question

I have 2 tables as shown:
I want to CONCAT the two tables by joining them and split them over the repetition of Row Number.
CREATE TABLE #portiontable (
PortionKey NVARCHAR(100),
RN INT,
)
CREATE TABLE #finaltable (
Value NVARCHAR(100),
RN INT,
)
INSERT INTO #finaltable (Value,RN)
VALUES ('KRM__21X0E',1),
('C',2),
('',3),
('',4),
('KRM__21X0E',1),
('C',2),
('',3),
('',4)
INSERT INTO #portiontable (PortionKey,RN)
VALUES ('100',1),
('0AD',2),
('D',3)
SELECT * FROM #finaltable f
SELECT * FROM #portiontable p
SELECT (SELECT ''+ ValuePortionKey
FROM (
SELECT f.RN,f.value,P.PortionKey, f.value + P.PortionKey AS ValuePortionKey
FROM #portiontable p
INNER JOIN #finaltable f ON p.rn = f.rn
) ft
FOR XML PATH('')) as PartSignature
DROP TABLE #portiontable
DROP TABLE #finaltable
The desired output is 2 rows:
PartSignature
KRM__21X0E100C0ADD
KRM__21X0J100K0ADD
The actual output is:
PartSignature
KRM__21X0E100C0ADDKRM__21X0J100K0ADD

Answer 1

Firstly, it seems that you have 2 sets of data in the #finaltable. You need another column to identify it as a set. I have added a ValueSet in the #finaltable.
And, I think your sample data does not correspond to the expected output. I have amended the sample data for #finaltable
And finally, using STRING_AGG to perform the string concatenation, you can then GROUP BY the new ValueSet
CREATE TABLE #portiontable
(
PortionKey NVARCHAR(100),
RN INT,
)
CREATE TABLE #finaltable
(
ValueSet INT,
Value NVARCHAR(100),
RN INT,
)
INSERT INTO #portiontable (PortionKey,RN)
VALUES ('100',1),
('0AD',2),
('D',3)
INSERT INTO #finaltable (ValueSet,Value,RN)
VALUES (1,'KRM__21X0E',1),
(1,'C',2),
(1,'',3),
(1,'',4),
(2,'KRM__21X0J',1),
(2,'K',2),
(2,'',3),
(2,'',4)
SELECT f.ValueSet,
STRING_AGG (f.Value + p.PortionKey, '') AS ValuePortionKey
FROM #portiontable p
INNER JOIN #finaltable f ON p.RN = f.RN
GROUP BY f.ValueSet
DROP TABLE #portiontable
DROP TABLE #finaltable
-- Result
1 KRM__21X0E100C0ADD
2 KRM__21X0J100K0ADD