遇到NULL值时显示所有行

试试这个。它可能不是你想要的100%的输出,但它给了你一个良好的开始。

您也可以在此处查看: http://www.sqlfiddle.com/#!6/f9eb8/1/0

SELECT
  P0.ID,
  ISNULL(MAX(P0.aa), '') as 'aa',
  ISNULL(MAX(P0.bb), '') as 'bb',
  ISNULL(MAX(P0.cc), '') as 'cc',
  ISNULL(MAX(P0.dd), '') as 'dd'
FROM
(
  SELECT
    ID,
    CASE type
      WHEN 'aa' THEN Value
      ELSE NULL
    END AS 'aa',
    CASE type
      WHEN 'bb' THEN Value
      ELSE NULL
    END AS 'bb',
    CASE type
      WHEN 'cc' THEN Value
      ELSE NULL
    END AS 'cc',
    CASE type
      WHEN 'dd' THEN Value
      ELSE NULL
    END AS 'dd'
  FROM
    blah
 ) P0
GROUP BY
  P0.ID