単一行の列値

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
  

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'