我正试图在这样的cuser表中显示数据
a_User
___________________
1, Ben,
2, Joe,
3, Tom,
User_group
______________
1, 1,
1, 2,
1, 3,
2, 2,
3, 1,
a_Group
________________
1, All Access,
2, Customer Service,
3, Finance,
所以它弹出像
____________________________________________
Ben, All Access, Customer Service, Finance
Joe, null, Customer Service, null
Tom, All Access, null, null
相反，我正在
____________________________________________
Ben, All Access, All Access, All Access,
Ben, Customer Service, Customer Service, Customer Service,
Ben, Finance, Finance, Finance
Joe, Customer Service, Customer Service, Customer Service,
Tom , All Access, All Access, All Access,
我一直在加入一个左外连接，但我不能让列与描述相关联。
select su.usernum,
su.username,
su.descr,
su.email,
sfg1.functiongroup,
sfg2.functiongroup,
sfg3.functiongroup
from a_user su
left outer join User_group suf on su.usernum = suf.usernum
left outer join a_group sfg1 on suf.fgroupnum = sfg1.fgroupnum
left outer join a_group sfg2 on suf.fgroupnum = sfg2.fgroupnum
left outer join a_group sfg3 on suf.fgroupnum = sfg3.fgroupnum
where sfg1.FGROUPNUM = 1
or sfg2.FGROUPNUM = 2
or sfg3.FGROUPNUM = 3;
任何想法都会非常方便，
感觉我错过了一些非常基本的东西。