如何在MySQL中将具有不同字段的两个表联接到单个表？

Question

I have two tables:

ORDERS
    OrderID    CustomerID    OrderDate
    543        2             2015-09-18
    621        37            2016-09-19
    209        77            2016-09-20

CUSTOMERS
    CustomerName    Country
    Alen            Germany
    Ana             Mexico
    Lisa            India

I want to join both tables in a new table named CustomerOrders as following format:

OrderID    CustomerID  OrderDate      CustomerName    Country
543        2           2015-09-18     Alen            Germany
621        37          2016-09-19     Ana             Mexico
209        77          2016-09-20     Lisa            India

How to list all records from two different tables to a new table?

Answer 1

You known about database normalization? You known about "first normal form", "second normal form"?

I don't explain it now. All explained here: https://en.wikipedia.org/wiki/Database_normalization

Answer 2

假设您的客户表具有主键customer_id。

select o.order_id,c.customer_name,o.order_date, c.customer_id, c.country o.* from orders o left join customers c on o.customer_id=c.customer_id