解释USING命令

Question

看一看...

http://search.mysql.com/search?site=refman-41&q=using&lr=lang_en

官方MySQL站点没有解释USING命令.

你能做到吗？

Answer 1

USING是连接语法中ON关键字的变体.此链接详细说明了这一点.在示例中,查询

SELECT C.First_Name, C.Last_Name, O.title
FROM Employee AS C
LEFT JOIN job as O USING (ID);

是完全相同的

SELECT C.First_Name, C.Last_Name, O.title
FROM Employee AS C
LEFT JOIN job as O ON C.ID = O.ID;