通过SQL连接三个表

Question

我有3个SQL表：

客户：

id
name
name2

书籍：

id
title
cID (contains the id of the customer)

销售：

id
value
bID (contains the id of the book)

如何连接3个表以得到这样的结果？

Customer name
Customer name 2
Book title
Sales value

Answer 1

因此：

select 
  c.name as "Customer name", 
  c.name2 as "Customer name 2", 
  b.title as "Book title", 
  s.value as "Sales value"
from 
  customers c 
  inner join books b on b.cID = c.id
  inner join sales s on s.bID = b.id

如果您的数据库不支持ANSI SQL概念“在列别名周围加上引号以允许它们具有空格”，请使用数据库通常使用的相关字符

Answer 2

Select c.name, c.name2, b.title, s.value from customers c 
left join books b on c.id = b.cID
left join sales s on b.id = b.bID