mysql按固定顺序排列

您可以使用以下任一方法来做到这一点：

ORDER BY FIND_IN_SET(id, '3,11,7,1')

要么

ORDER BY FIELD(id, 3, 11, 7, 1)

要么

ORDER BY CASE id WHEN 3 THEN 0     WHEN 11 THEN 1      WHEN 7 THEN 2      WHEN 1 THEN 3  ELSE 4         END