kolumnvärde i en enda rad

Här är ytterligare två metoder, bara för fullständighetens skull:

1. SELECT
     p.name,
     MAX(CASE t.phonetype WHEN 'work' THEN t.phoneno END) AS workphone,
     MAX(CASE t.phonetype WHEN 'home' THEN t.phoneno END) AS homephone,
     MAX(CASE t.phonetype WHEN 'mob' THEN t.phoneno END) AS mobilephone
   FROM people p
     INNER JOIN phones t ON p.Id = t.Id
   GROUP BY p.Id, p.Name
   

2. SELECT
     p.name,
     w.phoneno AS workphone,
     h.phoneno AS homephone,
     m.phoneno AS mobilephone
   FROM people p
     LEFT JOIN phones w ON p.Id = w.Id AND w.phonetype = 'work'
     LEFT JOIN phones h ON p.Id = h.Id AND h.phonetype = 'home'
     LEFT JOIN phones m ON p.Id = m.Id AND m.phonetype = 'mob'