Too many results in hierarchically query

Question

Hello all,
I'm searching for an idea to stop getting results 2, 3 and more times out of the following query
select
t.lvl,
t.syswflvl,
t.upper,
LPAD(' ', (lvl)*8)||t.code code,
LPAD(' ', (lvl)*8)||t.bezeichnung bezeichnung,
t.chk,
t.rang
from (
select '0' lvl, '0-'||to_char(syswftable,'0000000') syswflvl, '0- 0000000' upper, syscode code, bezeichnung, '' chk, 0 rang from wftable where (select count(wfm.syswftable) from wfm where wfm.syswftable = wftable.syswftable) > 0 union
select '1' lvl, '1-'||to_char(syswfm,'0000000') syswflvl, '0-'||to_char(syswftable,'0000000') upper, syscode code, kurzbez bezeichnung, anzeigefilter chk, 1 rang from wfm union
select '2' lvl, '2-'||to_char(syswfa,'0000000') syswflvl, '1-'||to_char(syswfm,'0000000') upper, syscode code, kurzbez bezeichnung, bedingung chk, rang from wfa union
select '3' lvl, '3-'||to_char(syswfc,'0000000') syswflvl, '2-'||to_char(syswfa,'0000000') upper, syscode code, kurzbez bezeichnung, bedingung chk, rang from wfc union
select '4' lvl, '4-'||to_char(syswfg,'0000000') syswflvl, '3-'||to_char(syswfc,'0000000') upper, syscode code, kurzbez bezeichnung, bedingung chk, rang from wfg
) t
where ((t.chk not like '%and 0%'
and trim(t.chk) not like '0%')
or t.chk is null)
and upper not like '%-'
connect by nocycle prior syswflvl = upper
order siblings by upper, syswflvl, rang
What happens is, that I get the results from level 0 one times, from level 1 two times, from level 2 three times etc.
What I'm try to achive is to get only the whole thing once.
Hope you can see what my problem is ;-)
Regards
Carsten

Answer 1

The effect of not having a start with clause in a hierarchical query is that a hierarchy is produced starting at every possible entry-point. So, you'll get the hierachy from node 1, the hierarchy from all nodes 2, the hierarchy from all nodes 3 and so one. Whether it starts with the correct one or not is not really relevant, as you already figured out that you get too much....
So, just believe it, add a start with clause...and your problems are gone.