MySQL 分组后查询每组最新的一条数据，并查出每组的总数

SELECT * FROM
        (select
        *from pf_module_work t
      left join  pf_module_work_history h on h.work_id = t.work_id
        WHERE h.id
        IN  (
        select max(id) from pf_module_work_history h GROUP BY h.creator  //子表根据userId分组，然后查出所有用户的最大的id记录，也就是最新的一条数据的id
        ) )  a,
        (SELECT h.creator ,count(h.creator) as commitTimes FROM pf_module_work_history h GROUP BY h.creator) AS b
        where a.creator = b.creator

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