mysql inner jion多表查询

select
vtiger_users.id,
vtiger_users.user_name,
vtiger_role.rolename
FROM
vtiger_users
inner join vtiger_role
inner join vtiger_user2role
on vtiger_users.id = vtiger_user2role.userid
and vtiger_user2role.roleid = vtiger_role.roleid

 select

　　字段1，字段2，字段3

from

表1

inner join 表2

inner join 表3 on

表1.字段 = 表2.字段

and 表2.字段 = 表3.字段