Question

在“图书”类别中提供的所有产品中，过去3个月内订购的百分比是多少？

ORDERS
order_id
customer_id
order_date
product_id

PRODUCTS
product_id
product_name
product_category
product_price

Answer 1

我假设你是在一个反击百分比之后。如果要比较值，则需要稍微更改下面的选择。以下是我将如何做到这一点。请注意，我没有运行它，因此您可能会遇到一些语法错误，但应该很容易修复它们。

WITH books AS (
  SELECT order_date
    FROM orders
    JOIN products
      ON orders.product_id = products.product_id
   WHERE products.product_category = 'books'
),
last_three_months AS (
  SELECT 0 as counter_1, count(*) AS counter_2
    FROM books
   WHERE order_date > DATEADD(MONTH, -3, GETDATE());
),
total_orders AS (
  select count(*) AS counter_1, 0 as counter_2
  FROM books
),
all_together AS (
 SELECT counter_1, counter_2
   FROM last_three_months
 UNION ALL
 SELECT counter_1, counter_2
   FROM total_orders
),
sale_sums AS (
  SELECT SUM(counter_2) AS counter_2, SUM(counter_1) AS counter_1
    FROM all_together
)
SELECT counter_2/counter_1 * 100
FROM sale_sums

Answer 2

尝试这个简单的查询。这是一个简单的PSQL。学习简单的语法，你就可以自己完成。

WITH ordersLastThree as
(
 Select o.* FROM PRODUCTS p,ORDERS o where p.product_id=o.product_id and
 p.product_category = [Books product_category] 
 and o.order_date >= DATEADD(MONTH, -3, GETDATE()) 
)
 Select (ISNULL((Select count(*) from ordersLastThree),1)*100) / count(o.*) as Result
 FROM PRODUCTS p,ORDERS o where p.product_id=o.product_id and
 p.product_category = [Books product_category]

Answer 3

首先你必须告诉我们你正在使用的数据库..

它会相应变化.. 如果它是Mysql和C＃fornt结束那么代码wiil

....通过sql查询接受返回的行到daatareader然后应用计算。我希望它能清除你的怀疑

查找订购产品的百分比

3 个答案: