MYSQL - Flatten Table Query

Du skal definere en GROUP BY klausul, og brug MAX samle for at få det output, du ønsker:

  SELECT listup.NodeNumber As Node, listup.Station As Extension,
         MAX(CASE WHEN VoiceServer = 1 THEN KeyDescription ELSE NULL END) AS 'Key1',
         MAX(CASE WHEN VoiceServer = 2 THEN KeyDescription ELSE NULL END) AS 'Key2',
         MAX(CASE WHEN VoiceServer = 3 THEN KeyDescription ELSE NULL END) AS 'Key3',
         MAX(CASE WHEN VoiceServer = 4 THEN KeyDescription ELSE NULL END) AS 'Key4',
         MAX(CASE WHEN VoiceServer = 5 THEN KeyDescription ELSE NULL END) AS 'Key5',
         MAX(CASE WHEN VoiceServer = 6 THEN KeyDescription ELSE NULL END) AS 'Key6',
         MAX(CASE WHEN VoiceServer = 7 THEN KeyDescription ELSE NULL END) AS 'Key7',
         MAX(CASE WHEN VoiceServer = 8 THEN KeyDescription ELSE NULL END) AS 'Key8',
         MAX(CASE WHEN VoiceServer = 9 THEN KeyDescription ELSE NULL END) AS 'Key9',
         MAX(CASE WHEN VoiceServer = 10 THEN KeyDescription ELSE NULL END) AS 'Key10'
    FROM listup
GROUP BY listup.NodeNumber As Node, listup.Station As Extension
ORDER BY listup.NodeNumber, listup.Station

NULL er at foretrække frem for en streng på nul.