用另一個表中的查詢刪除一個表中的行

Question

我在我的數據庫中有兩個表。

表客戶提供ID，名字，姓氏，地址......

和表訂單ID，idCustomer ...

，我想刪除客戶的所有訂單，其中的第一個名字是「約翰」

我如何編寫命令？

感謝

Answer 1

DELETE o 
FROM  Orders o 
INNER JOIN Customer c ON o.idCustomer = c.ID 
WHERE  c.firstName = 'john' 

Answer 2

Delete From 
    orders 
Where 
    Orders.firstName In 
     (Select 
      firstName 
     From 
      customers 
      Inner Join orders On customers.ID = orders.idCustomer 
     Where 
      customers.firstName = "john")