Oracle数据库如何实现左外联和右外联
create or replace view V_WTK_ALL as
select a.id, o.short as FindDeptName, u.realname as FindUserName, f.name as FindWay, o1.short as ProblemAtDeptName,
z.name as szzz, a.yhnr, s.name as SSZY, k.name as kind, w.name as whhg, a.zgcs, a.zgfzr, a.plandate, a.finishdate,
u1.realname as jdr, u2.realname as fxr, a.yqzt, a.yqdate, a.wtkzt
from WTK a, ORGANIZATION o, ORGANIZATION o1, OPERATORS u,OPERATORS u1,OPERATORS u2, Kind k, Findway f, SPfield s, SZZZ z, WHHG w
where a.finddeptid =o.id(+) and a.problematdeptid=o1.id(+) and a.finduserid=u.id(+) and a.jdr=u1.id(+) and a.fxr=u2.id(+)
and a.kindid=k.id(+) and a.findwayid=f.id(+) and a.spfieldid=s.id(+) and a.szzid =z.id(+) and a.whhgid=w.id(+)
有两个表
table1
user_id user_name user_ps教程s
1 aaa a
2 bbb b
3 ccc c
table2
user_id user_power
1 111000
2 000111
使用sql语句查询
正常状态:
select table1.user_id,
table1.user_name,
table2.user_power
from table1,table2
where table1.user_id = table2.user_id
但是这样检索到的数据只有两条:
user_id user_name user_power
1 aaa 000111
2 bbb 111000
输入你想转换的文字内容,
点击下面按钮进行在线转换。
select table1.user_id,table1.user_name,table2.user_power
from table1,table2
where table1.user_id (+)= table2.user_id
就可以得到如下的结果
user_id user_name user_power
1 aaa 000111
2 bbb 111000
3 ccc (null)
补充:数据库,Oracle教程