Answer 1

Answer 2

听起来我正在尝试为指定的用户（行）找到一个空列。并且，空列包含NULL。假设这是正确的并忽略了对正确设计的担忧，这里将返回包含NULL值的第一列的数字。

SELECT CASE
    WHEN I0 IS NULL THEN 0
    WHEN I1 IS NULL THEN 1
    WHEN I2 IS NULL THEN 2
    WHEN I3 IS NULL THEN 3
    WHEN I4 IS NULL THEN 4
    WHEN I5 IS NULL THEN 5
    WHEN I6 IS NULL THEN 6
    WHEN I7 IS NULL THEN 7
    WHEN I8 IS NULL THEN 8
    WHEN I9 IS NULL THEN 9
  END AS NextColumn
FROM MyTable
WHERE UserID = 'Me'
;

Answer 3

SELECT COALESCE(I0, I1, I2, I3, I4, I5, I6, I7, I8, I9) AS FirstNotNull
FROM MyTable