之前在项目中都是通过查询出基础数据，然后再业务层组装出TreeGrid对应的数据结构。但是个人感觉如果在提供树状结构展示的同时提供excel导出的共就比较麻烦，所以自己就写了一个。
----树形结构orgcode不能重复，所以用orgCode+subejctstages组装
select m.orgCode || n.subejctstages orgCode,
orgName,
orglevel,
case
when length(m.orgCode) = 6 and n.subejctstages is not null then
orgCode
else
pcode
end pcode,
subejctstages
from (select distinct a.code orgCode,
a.name orgName,
a.orglevel,
a.pcode
from org a
left join (select a.testid, a.testcampuscode
from subjectregister a
where a.testid = :testID
and a.testcampuscode like :orgCode
group by a.testid, a.testcampuscode
having count(1) > 0) c
on a.testid = c.testid
--and a.code = c.testcampuscode
and (a.code = c.testcampuscode or
a.code = substr(c.testcampuscode, 0, 5) or
a.code = substr(c.testcampuscode, 0, 2))
where a.testid = :testID1
and a.code like :orgCode1
and a.enable = :enable
and c.testcampuscode is not null) m
left join (
---如果要在查询结果中增加一列，并且这列的值为指定的几个值时，可以组装一个临时表
select '' subejctstages
from dual
union
select '1' subejctstages
from dual
union
select '2' subejctstages
from dual) n
on length(m.orgCode) = 6