SQL merging columns where only one column differ - sql

Question

I use SQL Server 2017 and have a simple query with joins that looks like this.
SELECT DISTINCT
[p].[MainTitle] AS Title,
[pe].[Name] AS JobName,
[ea].[Label] AS Stat
FROM
[Project] AS [P]
INNER JOIN
[ProjectExtended] AS [pe] ON [p].[ID] = [pe].[ProjectID]
INNER JOIN
[ExtAttributes] AS [ea] ON [pe].[AttributeID] = [ea].[ID]
...
WHERE
pe.date BETWEEN #start AND #end
AND [ea].Label IN ('A', 'B', 'C')
The result right know looks like this (JobName is different for every Title but always the same for the same Title)
+-----------+----------+--------------+
| Title | JobName | Stat |
+-----------+----------+--------------+
| BAMB | asdf | C |
| BIRT | fdsa | B |
| BIRT | fdsa | A |
| BOND | lofe | B |
+-----------+----------+--------------+
But I want it to show like this.
+-----------+----------+--------------+
| Title | JobName | Stat |
+-----------+----------+--------------+
| BAMB | asdf | C |
| BIRT | fdsa | B, A |
| BOND | lofe | B |
+-----------+----------+--------------+
I tried with different versions of CONCAT, STRING_AGG functions that you suggested in different threads, but no success. I only got to the point where it joins all the stats in last column - result was like A, B, C in every row.

Answer 1

This should help:
SELECT
[t].[Title] AS Title,
[t].[JobName] AS JobName,
STRING_AGG([t].[Stat], ',') AS Stat
FROM (
SELECT DISTINCT
[p].[MainTitle] AS Title,
[pe].[Name] AS JobName,
[ea].[Label] AS Stat
FROM
[Project] AS [P]
INNER JOIN
[ProjectExtended] AS [pe] ON [p].[ID] = [pe].[ProjectID]
FULL OUTER JOIN
[ExtAttributes] AS [ea] ON [pe].[AttributeID] = [ea].[ID]
...
WHERE
pe.date BETWEEN #start AND #end
AND [ea].Label IN ('A', 'B', 'C', NULL)
) t
GROUP BY
[t].[Title]
, [t].[JobName]
It says version 15 but hopefully is available on yours also
https://learn.microsoft.com/en-us/sql/t-sql/functions/string-agg-transact-sql?view=sql-server-ver15