您好所有我有如下表 -LEFT OUTER JOIN不工作
tr_resource作为资源 -
Resourceid name
135021 ABC
tr_charac作为chlev -
characid name
1 CH1
2 CH2
tr_characvalue作为cvlev -
characvalueid characid stringvalue
cv1 1 XX
cv2 2 YY
cv3 2 zz
tr_resourcecharac作为rchlev -
resourceid characvalueid
135021 cv2
当我运行下面的查询 -
select
res.name,
cvlev.stringvalue
from tr_resource res
left outer join tr_resourcecharac rchlev on res.RESOURCEID = rchlev.RESOURCEID
inner join tr_characvalue cvlev on rchlev.CHARACVALUEID = cvlev.CHARACVALUEID
inner join tr_charac chlev on chlev.CHARACID = cvlev.CHARACID and chlev.NAME = 'CH2'
where res.resourceid=135021
我得到的答案 -
name stringvalue
ABC YY
但是当我运行下面的查询,我没有得到任何答案 -
select
res.name,
cvlev.stringvalue
from tr_resource res
left outer join tr_resourcecharac rchlev on res.RESOURCEID = rchlev.RESOURCEID
inner join tr_characvalue cvlev on rchlev.CHARACVALUEID = cvlev.CHARACVALUEID
inner join tr_charac chlev on chlev.CHARACID = cvlev.CHARACID and chlev.NAME = 'CH1'
where res.resourceid=135021
我想获得回答r as -
name stringvalue
ABC null
您能否帮忙?
嗨Raniendu感谢您的回复,但用左外连接代替内连接没有工作 – anidesh