sql - SQL - 分组到列更新

Question

我在玩AdvantureWorksDB，但我没有实际销售额值SalesOrderDetail。此行应该包含LineTotal按订单 ID 的聚合。

我需要将这些值输入到每个订单 ID 行的实际销售额列中：

select SUM(LineTotal) as ActualSales
from Sales.SalesOrderDetail
group by SalesOrderID

Answer 1

您需要将要分组的字段添加到查询中：

select SalesOrderID, sum(LineTotal) as ActualSales 
from SalesOrderDetail 
group by SalesOrderID

Answer 2

你可以UPDATE这样JOIN：

UPDATE od
SET od.ActualSalesColumn = g.ActualSales
FROM Sales.SalesOrderDetail od
INNER JOIN
(
    SELECT 
      SalesOrderDetail, 
      SUM(LineTotal) as ActualSales 
    FROM Sales.SalesOrderDetail 
    GROUP BY SalesOrderID
) g ON od.SalesOrderID = g.SalesOrderID;

或者：使用 CTE：

WITH ActualSales
AS
(
     SELECT 
       SalesOrderDetail, 
       SUM(LineTotal) as ActualSales 
     FROM Sales.SalesOrderDetail 
     GROUP BY SalesOrderID
)
UPDATE od
SET od.ActualSalesColumn = g.ActualSales
FROM Sales.SalesOrderDetail od
INNER JOIN ActualSales g ON od.SalesOrderID = g.SalesOrderID;

Answer 3

UPDATE x
SET x.ActualSales = x.NewActualSales
FROM (
      SELECT ActualSales, SUM(LineTotal) OVER (PARTITION BY SalesOrderID) AS NewActualSales
      FROM Sales.SalesOrderDetail
      ) x