如何通过MySQL语法中的MTM连接访问多个表?

时间:2015-02-02 12:09:33

标签: mysql sql

我正在尝试通过MySQL数据库上的MTM连接访问多个表。

这是一个示例图,它代表我的表: enter image description here

我想通过一个Sql-Statement访问User,Skill和SkillLevel。有没有办法使用多个INNER JOIN'S?

我尝试过这样的事情:

SELECT * FROM User, Skill, SkillLevel 
INNER JOIN Members ON User.UserMail = Members.UserMail 
INNER JOIN Members ON Skill.SkillID = Members.SkillID
INNER JOIN Members ON SkillLevel.SkillLevelID = Members.SkillLevelID 
WHERE Members.TeamID = 123
你能帮助我吗?

修改

我之后设置了表格。只有一个或多个,我总是得到

"Not unique table/alias: 'projectmembers'"

1 个答案:

答案 0 :(得分:0)

感谢jarlh我找到了解决方案!诀窍是,通过User,Skill和SkillLevel加入。同样由于Where Statement,我不得不

Select * FROM Members

解决方案是:

SELECT * FROM Members
JOIN User ON Members.UserMail = User.UserMail 
JOIN Skill ON Members.SkillID = Skill.SkillID
JOIN SkillLevel ON Members.SkillLevelID = SkillLevel.SkillLevelID 
WHERE Members.TeamID = 123 ;