如何使用INNER JOIN为代码添加WHERE条件？

Question

我不知道如何为AS列添加where条件，是否有

我尝试使用方括号的列，但它不起作用

SELECT   
    Suppliers.CompanyName,
    SUM([Order Details].UnitPrice*Quantity) AS [Total sales]
FROM
    [Order Details]  
INNER JOIN 
    Products ON products.ProductID = [Order Details].ProductID
INNER JOIN 
    Suppliers ON Products.SupplierID = Suppliers.SupplierID
WHERE 

GROUP BY 
    Suppliers.CompanyName
ORDER BY 
    2 DESC;

我只想看到总销量超过10,000

Answer 1

您需要在HAVING子句中添加条件：

SELECT  
  Suppliers.CompanyName, 
  SUM([Order Details].UnitPrice*Quantity)AS [Total sales]
FROM [Order Details] 
INNER JOIN 
Products ON products.ProductID= [Order Details] .ProductID
INNER JOIN
Suppliers ON Products.SupplierID= Suppliers.SupplierID
GROUP BY Suppliers.CompanyName
HAVING SUM([Order Details].UnitPrice*Quantity) > 10000
Order by 2 desc;

Answer 2

你只需要添加一个HAVING子句而不是WHERE子句，

在GROUP BY之后

HAVING SUM([Order Details].UnitPrice*Quantity) > 10000

在您的SQL语句中：

SELECT  Suppliers.CompanyName, SUM([Order Details].UnitPrice*Quantity) AS [Total sales]    
  FROM [Order Details]     
 INNER JOIN 
        Products ON products.ProductID= [Order Details] .ProductID
 INNER JOIN
        Suppliers ON Products.SupplierID= Suppliers.SupplierID
GROUP BY Suppliers.CompanyName
HAVING SUM([Order Details].UnitPrice*Quantity) > 10000
ORDER BY 2 desc