| 时间字段在sql语句中只能查询出有记录的数，如何让他按照顺序补全？ h0-h23这个字段库中没有，怎么拿到？或者其他的方法获得显示值是h0-h23,真实值为0-23的一个序列？ 没有值的情况下怎么让它为零？ select substr(t,1,7) day,substr(t,12,2) time ,count(*) num from (select id,fromtime t from stable where fromtime>='2018-04-09 00:00:00' and fromtime <='2018-05-14 23:59:59') group by substr(t,1,7),substr(t,12,2) order by substr(t,1,7),substr(t,12,2) 结果图2 怎么拿解决这三个问题？ |
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