MSQL数据库多表查询问题
时这样的,我要做权限管理,要分模块,但是这个要多表查询,我在数据库写了好久都没写出查询语句出来,请大侠帮忙
=================================================================================================================
现有5张表,
用户表sub(id,name,pass,role_id)role_id为角色id
角色表role_table(role_id,name)
模块表module(md_id,md_name)md_id为模块名称
功能表auy(auy_id,md_id,auy_name,auy_url)auy_id为功能id,auy_url为功能路径
角色功能关联表role_auy(role_id,auy_id)
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现在知道角色id,通过角色id查找相应的功能,然后显示着相应的模块下面,如果直接把所有的功能一次查询出来,我就已经弄好了,但是经理让我把功能放在相应的模块下面,希望各位大侠,告诉我怎样查询的思路,让我不再纠结,谢谢大家
------解决方案--------------------
也不贴结果,试试下面。
- SQL code
select a.role_id,a.auy_id,a.auy_name,m.md_name from role_auy as ra left join auy as a on a.auy_id=ra.auy_id inner left join module as m on m.md_id=a.md_id where ra.role_id=1;<br><font color="#e78608">------解决方案--------------------</font><br><br><br>
- SQL code
SELECT * FROM role_auy AS ra LEFT JOIN auy AS a ON ra.auy_id = a.auy_id LEFT JOIN module AS m ON a.md_id = m.md_id WHERE ra.role_id = '角色ID'如果还要关联用户表 就在 WHERE前面加 LEFT JOIN sub AS s ON ra.role_id = s.role_id<br><font color="#e78608">------解决方案--------------------</font><br>功能放在相应的模块下面,表示模块id 是已知且固定的<br>又角色id已知<br>则连接应使用内连接或逗号连接,因为是要取得存在的功能<br><br>
- SQL code
select* from role_auy, auy where role_auy.auy_id=auy.auy_id and role_auy.role_id=角色id and auy.md_id=模块id<div class="clear"> </div>

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