Question

我正在使用的两个表

Orderdetails
ordernumber, productnumber, productcode, quantityordered, priceEach

Orders
ordernumber, orderdate (labeled as yyyy-mm-dd)

我了解获得收入Sum( quantityOrdered * priceEach ) as TotalRevenue。

难以按月分组并连接两个表。

谢谢

Answer 1

在标准SQL中，您可以这样做：

select extract(year from o.orderdate) as yyyy,
       extract(month from o.orderdate) as mm,
       sum(ol.quantityOrdered * ol.priceEach) as total
from orders o join
     orderlines ol
     on o.ordernumber = ol.ordernumber
group by extract(year from o.orderdate), extract(month from o.orderdate)
order by yyyy, mm;

众所周知，数据库对日期/时间功能的支持多种多样。许多支持简单的year()和month()函数。许多人都支持其他机制来做同样的事情。

在MySQL中，您可以使用year()和month()函数：

select year(o.orderdate) as yyyy,
       month(o.orderdate) as mm,
       sum(ol.quantityOrdered * ol.priceEach) as total
from orders o join
     orderlines ol
     on o.ordernumber = ol.ordernumber
group by year(o.orderdate), 
order by yyyy, mm;

Answer 2

我将使用T-SQL。将T-SQL转换为其他SQL方言很简单。

首先，通过将所有OrderDetails按OrderNumber和SUM分组其值来获得每个订单的总收入：

SELECT
    OrderNumber,
    SUM( QuantityOrdered * PriceEach ) AS OrderValue
FROM
    OrderDetails
GROUP BY
    OrderNumber

这给了我们这个输出：

OrderNumber    OrderValue
          1        123.00
          2        456.00   
          3         50.00
          4       1024.00

然后用JOIN Orders来获得他们的OrderDate：

SELECT
    Orders.OrderNumber,
    Orders.OrderDate,
    COALESCE( ov.OrderValue, 0 ) AS OrderValue
FROM
    OrderDetails
    LEFT OUTER JOIN
    (
        SELECT
            OrderNumber,
            SUM( QuantityOrdered * PriceEach ) AS OrderValue
        FROM
            OrderDetails
        GROUP BY
           OrderNumber
    ) AS ov ON ov.OrderNumber = Orders.OrderNumber

这给了我们这个输出：

OrderNumber   OrderDate  OrderValue
          1   2018-02-03     123.00
          2   2018-05-09     456.00   
          3   2018-02-04      50.00   
          4   2018-06-08    1024.00

然后，我们要按行（月和月的元组）对行进行分组，并在每个组中找到SUM中的OrderValue。我们可以不再使用OrderNumber列了。我们也可以添加一个COUNT。然后ORDER BY SUM

SELECT
    YEAR( Orders.OrderDate ) AS [Year],
    MONTH( Orders.OrderDate ) AS [Month],
    COUNT( * ) AS [OrderCount],
    SUM( COALESCE( ov.OrderValue, 0 ) ) AS RevenueInMonth 
FROM
    OrderDetails
    LEFT OUTER JOIN
    (
        SELECT
            OrderNumber,
            SUM( QuantityOrdered * PriceEach ) AS OrderValue
        FROM
            OrderDetails
        GROUP BY
           OrderNumber
    ) AS ov ON ov.OrderNumber = Orders.OrderNumber
GROUP BY
    YEAR( Orders.OrderDate ),
    MONTH( Orders.OrderDate )
ORDER BY
    RevenueInMonth DESC

这给了我们这个输出：

Year    Month   OrderCount RevenueInMonth
2018        6            1        1024.00
2018        5            1         456.00
2018        2            2         173.00

Answer 3

您可以将month和year函数的分组一起使用

select concat(month(orderdate),'/',year(orderdate)) as term,
       Sum( quantityOrdered * priceEach ) as TotalRevenue
  from Orders o
  left join Orderdetails d on o.ordernumber = d.ordernumber
 group by term;

Rextester Demo

按产生的收入金额对月份排序SQL

3 个答案: