Question

我在mySQL数据库中有两个表

Table 1 [Orders]
DateOpened (date), 
revenue

Table 2 [Movements]
DateStarted (date), 
DateStopped (date)

对于任何给定日期，表1中可能有0个或更多条目，对于表2，DateStarted或DateStopped可能有0个或更多条目（DateStarted和DateStopped都可以是相同天或不同）

我想查询这些表的日期范围（例如：一个月），并获得每个日期的结果集，其中包含此表单中的某些数据：

date, sum(revenue), num_orders (count of orders for the date), num_movements (count of movements for the date)

我创建了两个单独的查询来完成每个部分但我无法弄清楚如何组合它们以便我可以实现单个高效查询而不必在代码中合并结果集。我似乎要挂断的是正确应用count（）函数。

以下是现有的有效查询：

select count(*) as total_movements, movement_date
from (
    select dropoffdate as movement_date
    from bb_movement
    where (dropoffdate >= '2013-01-01' and dropoffdate <= '2013-06-30') 
    union all
    select pickupdate as movement_date
    from bb_movement
    where (pickupdate >= '2013-01-01' and pickupdate <= '2013-06-30')
) as t3
group by movement_date
order by movement_date asc

select count(*) as num_orders, sum(order_amount) as revenue, dateopened as date_opened
from bb_order
where (dateopened >= '2013-01-01' and dateopened <= '2013-06-30') 
group by dateopened
order by dateopened asc

CREATE TABLE IF NOT NOT EXISTS bb_movement（ movementid int（10）unsigned NOT NULL AUTO_INCREMENT， orderid int（10）unsigned NOT NULL COMMENT dropoffdate日期非空， pickupdate日期非空）

CREATE TABLE IF NOT NOT EXISTS bb_order（ orderid int（10）unsigned NOT NULL AUTO_INCREMENT， movementid int（10）unsigned NOT NULL， dateopened日期非空， order_amount浮动NOT NULL DEFAULT'0' }

Answer 1

解决：它需要在主选择

中将源表与适当的聚合函数结合起来

 SELECT mv_date, sum(mv_count), sum(order_count), sum(order_revenue)
FROM (
    select dateopened as mv_date, 0 as mv_count, count(*) as order_count, sum(order_amount) as order_revenue
    from bb_order
    where (dateopened >= '2013-01-01' and dateopened <= '2013-06-30')
    group by mv_date
    union all
    SELECT dropoffdate AS mv_date, COUNT( * ) AS mv_count, 0 as order_count, 0 as order_revenue
    FROM bb_movement
    WHERE (dropoffdate >=  '2013-01-01' AND dropoffdate <=  '2013-06-30')
    group by mv_date
    UNION  all
    SELECT pickupdate AS mv_date, COUNT( * ) AS mv_count, 0 as order_count, 0 as order_revenue
    FROM bb_movement
    WHERE (pickupdate >=  '2013-01-01' AND pickupdate <=  '2013-06-30')
    group by mv_date
 ) mv
group by mv_date
order by mv_date

将两个查询与count函数组合用于单个结果集

1 个答案: