Question

我在ms-sql 2008中有2个表

Data_CardCustomer
它有＆gt;＆gt; CustomerId，Code，Name，...等字段

Data_ActionPriceList
它有＆gt;＆gt; CustomerId，StockId，Price1，Price2，Price3字段

我想汇总所有客户记录的所有价格如果customerId在DataActionPriceList表中没有价格，则它将返回零。

Code,Price1,Price2,Price3

当前查询

SELECT Code,
Isnull((select Price1 from Data_ActionPriceList where Data_ActionPriceList.CustomerId=Data_CardCustomer.CustomerId and StockId=10005 ),0) As price1,
Isnull((select Price2 from Data_ActionPriceList where Data_ActionPriceList.CustomerId=Data_CardCustomer.CustomerId and StockId=10005 ),0) As price2, 
Isnull((select Price3 from Data_ActionPriceList where Data_ActionPriceList.CustomerId=Data_CardCustomer.CustomerId and StockId=10005 ),0) As price3 
FROM Data_CardCustomer

有更简单的方法吗？

Answer 1

SELECT Data_CardCustomer.Code,
    Isnull(Data_ActionPriceList.Price1 ,0) As price1,
    Isnull(Data_ActionPriceList.Price2 ,0) As price2, 
    Isnull(Data_ActionPriceList.Price3 ,0) As price3 
FROM Data_CardCustomer 
left join Data_ActionPriceList on Data_ActionPriceList.CustomerId=Data_CardCustomer.CustomerId and StockId=10005

Answer 2

在你的问题标题中，你的想法正确。

SELECT
    dcc.Code,
    Isnull(dapl.Price1, 0) As price1,
    Isnull(dapl.Price2, 0) As price2,
    Isnull(dapl.Price3, 0) As price3

FROM
    Data_CardCustomer dcc LEFT JOIN Data_ActionPriceList dapl ON dapl.CustomerId = dcc.CustomerId

AND dapl.StockId = 10005

请注意：您也可以使用JOIN代替LEFT JOIN，具体取决于您的预期结果。使用JOIN，您只会获得两个表中包含相应条目的行，而您将使用Data_CardCustomer从LEFT JOIN检索所有行。

MSSQL LEFT OUTER JOIN更简单的方法

2 个答案: