选择正确的查询答案

【问题标题】：Chosing the right query选择正确的查询
【发布时间】：2015-04-02 14:21:26
【问题描述】：

我必须构建一个查询，该查询将为客户创建一个表 - 'Frank Spencer'（您将在下面的客户表中看到他）。

新表应该包含客户曾经购买过的每件产品的总和，排除那些尚未发货的订单，每件产品在新表中只出现一次。

我的表格如下。

您能告诉我以下哪个是最好的吗？

a)with customer as (select * from customers where lower(CustomerName) = 'frank spencer'),customerorders as(select OrderId from orders o where o.CustomerId in(select CustomerId from customer) and OrderShipped = 'True') select sum(oi.QuantityOrdered) as TotalOrdered, s.ItemName into franksorders from orderitems oi join stock s on oi.StockItemId = s.StockItemId where OrderId in(select * from customerorders) group by ItemName order by ItemName

b)with customer as (select * from customers where lower(CustomerName) = 'frank spencer') join customerorders as(select OrderId from orders o where o.CustomerId in(select CustomerId from customer) and OrderShipped = 'True') select total(oi.QuantityOrdered) as TotalOrdered, s.ItemName into new table franksorders using orderitems oi join stock s on oi.StockItemId = s.StockItemId where OrderId in(select * from customerorders) group by ItemName order by ItemName

c)with customer (select * from customers where 'frank spencer' in (CustomerName)) with customerorders (select OrderId from orders o where o.CustomerId in(select CustomerId from customer) and OrderShipped = 'True') select sum(oi.QuantityOrdered) as TotalOrdered, s.ItemName create table franksorders using orderitems oi join stock s on oi.StockItemId = s.StockItemId where OrderId in(select * from customerorders) group by ItemName order by ItemName

d)using customer with (select * from customers where CustomerName = 'frank spencer' and customerorders with(select OrderId from orders o where o.CustomerId in(select CustomerId from customer) then OrderShipped = 'True') select sum(oi.QuantityOrdered) as TotalOrdered, s.ItemName into franksorders from orderitems oi join stock s on oi.StockItemId = s.StockItemId where OrderId in(select * from customerorders) group by ItemName order by ItemName

【问题讨论】：

在你的测试中，哪一个在最短的时间内返回了想要的结果？
你只是复制了一些学校任务并想要得到答案...
这看起来非常像家庭作业。但撇开这些不谈，“最佳”的定义是什么？您实际尝试过什么？
我认为整个概念存在很大缺陷。这是存储计算出来的信息，从长远来看，这将是痛苦的。您将不得不设计各种代码以使该表保持最新。这将更适合作为视图而不是持久表。
E) 以上所有！

标签： sql sql-server tsql subquery

【解决方案1】：

B、C 和 D 中有一个 USING，据我所知，SQL Server 不支持。使用是，但不是使用。所以答案是A。下次你可以使用poorsql.com这样格式化你的代码，这样更容易发现错误。

WITH customer
AS (
    SELECT *
    FROM customers
    WHERE lower(CustomerName) = 'frank spencer'
    )
    ,customerorders
AS (
    SELECT OrderId
    FROM orders o
    WHERE o.CustomerId IN (
            SELECT CustomerId
            FROM customer
            )
        AND OrderShipped = 'True'
    )
SELECT sum(oi.QuantityOrdered) AS TotalOrdered
    ,s.ItemName
INTO franksorders
FROM orderitems oi
INNER JOIN stock s ON oi.StockItemId = s.StockItemId
WHERE OrderId IN (
        SELECT *
        FROM customerorders
        )
GROUP BY ItemName
ORDER BY ItemName

【讨论】：