我有三个表:如何计算在select语句的列共有来自其他表值
CustOrder:
id, CreateDate, Status
DenominationOrder:
id, DenID, OrderID
面额:
id, amount
我想创建基于所有这些表的视图,但应该有一个附加列即Total
应该在那里,其可以计算出每个订单的量的总和。
例如
- 顺序1总面额3,总量= 250 + 250 + 250 = 750
- 顺序2种总面额2,总量= 250 + 250 = 500
是否有可能?
我有三个表:如何计算在select语句的列共有来自其他表值
CustOrder:id, CreateDate, Status
DenominationOrder:id, DenID, OrderID
面额:id, amount
我想创建基于所有这些表的视图,但应该有一个附加列即Total
应该在那里,其可以计算出每个订单的量的总和。
例如
是否有可能?
我试着猜测你的表的关系(和数据量太大,你没有提供任何样本):
SELECT co.id,
COUNT(do.DenID) AS `Total denominations`,
SUM(d.amount) AS `Total amount`
FROM CustOrder co
INNER JOIN DenominationOrder do ON co.id = do.OrderId
INNER JOIN Denomination d ON do.DenId = d.id
GROUP BY co.id
我已经尝试过这一个,但它提供了所有不是逐行的总和:-SELECT总和(d.amount)作为从CustOrder o,DenominationOrder den,面额d其中o._id = den.OrderID和d._id = den.DenID – Fundi 2012-04-11 13:28:38
@Fundi:编辑你的问题发布样本数据,我们无法工作,我们认为你有... – Marco 2012-04-11 13:29:49
@Fundi:你发布的评论是什么查询?这是不对的!!你必须使用我的查询,而不是你的!你使用(在你的查询结束时)'AND o._id = 2',所以你只能得到order = 2!更多:请不要使用'WHERE'条件来替换'JOIN',请!!! – Marco 2012-04-11 13:30:45
试试这个:
SELECT o.CreateDate, COUNT(o.id), SUM(d.amount) AS 'Total Amount'
FROM CustOrder o
INNER JOIN DenominationOrder do ON o.id = do.OrderID
INNER JOIN Denomination d ON do.DenId = d.id
GROUP BY o.CreateDate
另一种方法这个,通过使用CTE,像这样:
;WITH CustomersTotalOrders
AS
(
SELECT o.id, SUM(d.amount) AS 'TotalAmount'
FROM CustOrder o
INNER JOIN DenominationOrder do ON o.id = do.OrderID
INNER JOIN Denomination d ON do.DenId = d.id
GROUP BY o.id
)
SELECT o.id, COUNT(ot.id) AS 'Orders Count', ot.TotalAmount
FROM CustOrder o
INNER JOIN CustomersTotalOrders ot on o.id = ot.id
INNER JOIN DenominationOrder do ON ot.id = do.OrderID
INNER JOIN Denomination d ON do.DenId = d.id
GROUP BY o.id, ot.TotalAmount
这会给你:
id | Orders Count | Total Amount
-------+---------------+-------------
1 3 750
2 2 500
,什么是你已经尝试在SELECT语句(或正在)? – 2012-04-11 13:12:09