MySql查询时日期补全(连续)的一种方法

SELECT od.date,od.orderCount

FROM (

SELECT DATE_FORMAT (order_time, '%Y-%m-%d') date,

count(*) orderCount FROM order WHERE order_time > '开始时间' andorder_time < '结束时间' GROUPBYDATE_FORMAT (order_time, '%Y-%m-%d')

UNION (SELECT0, '2017-03-01')

UNION (SELECT0, '2017-03-02')

UNION (SELECT0, '2017-03-03')

UNION (SELECT0, '2017-03-04') -- 很多个UNION......

) AS od GROUPBY od.date ORDERBY od.date ASC