# SQL RIGHT JOIN 关键字

RIGHT JOIN 关键字从右表（table2）返回所有的行，即使左表（table1）中没有匹配。如果左表中没有匹配，则结果为 NULL。

### SQL RIGHT JOIN 语法

     SELECT column_name(s)
     FROM table1
     RIGHT JOIN table2
     ON table1.column_name=table2.column_name;

或：

     SELECT column_name(s)
     FROM table1
     RIGHT OUTER JOIN table2
     ON table1.column_name=table2.column_name;

注释：在某些数据库中，RIGHT JOIN 称为 RIGHT OUTER JOIN。

## 演示数据库

在本教程中，我们将使用众所周知的 Northwind 样本数据库。

下面是选自 "Orders" 表的数据：

OrderID | CustomerID | EmployeeID | OrderDate | ShipperID
--- | --- | --- | --- | ---
10308 | 2 | 7 | 1996-09-18 | 3
10309 | 37 | 3 | 1996-09-19 | 1
10310 | 77 | 8 | 1996-09-20 | 2

选自 "Employees" 表的数据：

EmployeeID | LastName | FirstName | BirthDate | Photo | Notes
--- | --- | --- | --- | --- | ---
1 | Davolio | Nancy | 12/8/1968 | EmpID1.pic | Education includes a BA in psychology.....
2 | Fuller | Andrew | 2/19/1952 | EmpID2.pic | Andrew received his BTS commercial and....
3 | Leverling | Janet | 8/30/1963 | EmpID3.pic | Janet has a BS degree in chemistry....

## SQL RIGHT JOIN 实例

下面的 SQL 语句将返回所有员工及他们处理的订单：

## 实例

     SELECT Orders.OrderID, Employees.FirstName
    FROM Orders
    RIGHT JOIN Employees
    ON Orders.EmployeeID=Employees.EmployeeID
    ORDER BY Orders.OrderID;

注释：RIGHT JOIN 关键字从右表（Employees）返回所有的行，即使左表（Orders）中没有匹配。