SQL-帶有JOIN的SELECT語句

Question

我正在使用Northwind數據庫，因此無法管理以下查詢-

select *
from customers
    join orders
        on orders.customerID = customers.customerID
    join [Order Details]
        on orders.OrderID = [Order Details].orderID
    join Products (select Products.productID, Products.ProductName from Products)
        on [Order Details].productID = Products.productID
order by customers.customerID

我收到一條錯誤消息，指出第7行中的select語法不正確。

我想做的是，在加入“產品”表時，它不會顯示所有列，而只會顯示ProductName和ProductID。

有人可以解釋我在做什么錯嗎？ 謝謝！

Answer 1

您首先需要指定子查詢，然后再指定別名。

select *
from customers
    join orders
        on orders.customerID = customers.customerID
    join [Order Details]
        on orders.OrderID = [Order Details].orderID
    join (select Products.productID, Products.ProductName from Products) Products 
        on [Order Details].productID = Products.productID
order by customers.customerID

更改

join Products (select Products.productID, Products.ProductName from Products) 

至

join (select Products.productID, Products.ProductName from Products) Products 

Answer 2

您可能想嘗試一下：

select *
from customers
    join orders
        on orders.customerID = customers.customerID
    join [Order Details]
        on orders.OrderID = [Order Details].orderID
    join (select Products.productID, Products.ProductName from Products) Products
        on [Order Details].productID = Products.productID
order by customers.customerID