SQL SERVER: Multiple Rows into single row with comma seperated usinng STUFF

SQL SERVER: multiple rows into comma separated values using STUFF

The FOR XML PATH is the bit of magic that creates a concatenated
string from a result set.

Below is example

CREATE TABLE #tbl (c1 VARCHAR, c2 VARCHAR)

go

INSERT INTO #tbl VALUES('a',2)

INSERT INTO #tbl VALUES ('b',4)

SELECT ', ' + c1

from #tbl

for XML PATH('')

Output:

, a, b