Question

我有两个表：item_status_log和items。 items表具有itemid，status和ordertype列。 item_status_log表具有itemid，date_time，new_status和old_status。基本上，当在我的程序中更改状态时，会在item_status_log中记录一条记录，其中包含旧状态，新状态和date_time。

我想要的是能够查看按更新日期分组的项目表。我有以下sql工作完美：

select to_char(date_time, 'MM-DD-YYYY') as "Shipment Date", count(*) as "TOTAL Items"
from item_status_log i where old_status = 'ONORDER' 
group by "Shipment Date" 
order by "Shipment Date" desc

这给了我

Shipment Date  |   TOTAL Items
------------------------------
09/02/2014     |   4
09/01/2014     |   23

但是，我想在上面的表中添加2列，这样可以分解“INVENTORY”和“ORDER”的items表中有多少项具有状态。

我正在寻找：

 Shipment Date  |   TOTAL Items  |  Inventory   |  Ordered 
 ---------------------------------------------------------
 09/02/2014     |   4            |        3     |      1
 09/01/2014     |   23           |       20     |      3

这是我正在尝试的，但是让'子查询使用未分组的列“i.date_time”来自外部查询'错误

select to_char(date_time, 'MM-DD-YYYY') as "Shipment Date", count(*) as "TOTAL Items",
(select count(*) from item_status_log t 
where date(t.date_time) = date(i.date_time) and itemid in (select itemid 
from items where  ordertype = 'ORDER')) as "Customer",
(select count(*) from item_status_log t 
where date(t.date_time) = date(i.date_time) and itemid in (select itemid 
from items where  ordertype = 'INVENTORY')) as "Inventory"
from item_status_log i where old_status = 'ONORDER' 
group by "Shipment Date" 
order by "Shipment Date" desc

Answer 1

我认为你只需要条件聚合：

select to_char(date_time, 'MM-DD-YYYY') as "Shipment Date", count(*) as "TOTAL Items",
       sum(case when i.ordertype = 'ORDER' then 1 else 0 end) as NumOrders,
       sum(case when i.ordertype = 'INVENTORY' then 1 else 0 end) as NumInventory
from item_status_log il join
     items i
     on il.itemid = i.itemid
where old_status = 'ONORDER' 
group by "Shipment Date" 
order by "Shipment Date" desc;

Answer 2

尝试：

select to_char(date_time, 'MM-DD-YYYY') as "Shipment Date",
       count(*) as "TOTAL Items",
       sum(case when ordertype = 'INVENTORY' then 1 else 0 end) as "Inventory",
       sum(case when ordertype = 'ORDER' then 1 else 0 end) as "Ordered"
  from item_status_log i
 where old_status = 'ONORDER'
 group by "Shipment Date"
 order by "Shipment Date" desc

子查询使用来自外部查询的未分组列“i.date_time”

2 个答案: