mysql - Order By 和 Group By

Question

是否有一种有效的方法来进行排序依据和分组依据，以便您从每个组(从排序依据)中获得特定项目。

//This is the best way i have come up with.
SELECT D.*
FROM (
    SELECT *
    FROM devices
    ORDER BY time
) AS D
GROUP BY D.location

Answer 1

这对我有用

SELECT *
FROM (SELECT *
      FROM col
      ORDER BY col DESC,date DESC)a
GROUP BY col