Hur kombinerar jag data från flera rader till en?

Använda PIVOT Du kan göra följande

With SampleData AS 
(
SELECT 'Team1' as Team , 'example@sqldat.com' as email, 'A' as Groups
UNION SELECT 'Team1' as Team , 'example@sqldat.com' as email, 'B' as Groups
UNION SELECT 'Team1' as Team , 'example@sqldat.com' as email, 'C' as Groups
UNION SELECT 'Team2' as Team , 'example@sqldat.com' as email, 'A' as Groups
UNION SELECT 'Team2' as Team , 'example@sqldat.com' as email, 'B' as Groups
UNION SELECT 'Team2' as Team , 'example@sqldat.com' as email, 'C' as Groups
)
SELECT Team, A, B,C FROM 
(SELECT * FROM SampleData) source
PIVOT
(MAX(email) FOR Groups IN ([A], [B], [C]) )as pvt

Producerar

Team  A                B                C
----- ---------------- ---------------- ----------------
Team1 example@sqldat.com example@sqldat.com example@sqldat.com
Team2 example@sqldat.com example@sqldat.com example@sqldat.com

Se ett fungerande Data.SE-exempel

I en DB som inte stöder PIVOT kan du istället göra flera kopplingar till din tabell. Även om du kanske vill ändå, eftersom som GBN påpekade, eftersom vi inte använder ett aggregat.

With SampleData AS 
(
SELECT 'Team1' as Team , 'example@sqldat.com' as email, 'A' as Groups
UNION SELECT 'Team1' as Team , 'example@sqldat.com' as email, 'B' as Groups
UNION SELECT 'Team1' as Team , 'example@sqldat.com' as email, 'C' as Groups
UNION SELECT 'Team2' as Team , 'example@sqldat.com' as email, 'A' as Groups
UNION SELECT 'Team2' as Team , 'example@sqldat.com' as email, 'B' as Groups
UNION SELECT 'Team2' as Team , 'example@sqldat.com' as email, 'C' as Groups
)

SELECT 
    source.Team,
    A.email,
    B.email,
    C.email
FROM 
    (SELECT DISTINCT TEAM From SampleData) source
    LEFT JOIN SampleData A 
    ON source.Team = A.Team
     AND A.GROUPS = 'A'
    LEFT JOIN SampleData B 
    ON source.Team = B.Team
    AND B.GROUPS = 'B'
    LEFT JOIN SampleData C 
    ON source.Team = C.Team
    AND C.GROUPS = 'C'

Se ett fungerande Data.SE-exempel