Re: Hierarchical queries - Mailing list pgsql-general

On Sat, 10 Jan 2004 Anton.Nikiforov@loteco.ru wrote:

> Hello Oleg and thanks for the link, but i could not understand how to
> get path from one point of the tree to another?

have you read documentation ? Get all childrens - ltree <@ ltree,
for example:

ltreetest=# select path from test where path <@ 'Top.Science';
                path
------------------------------------
 Top.Science
 Top.Science.Astronomy
 Top.Science.Astronomy.Astrophysics
 Top.Science.Astronomy.Cosmology
(4 rows)

You should provide us example of your data and query, so we could help you.

> Anyway thanks :)
>
> Best regards,
> Anton
> OB> Look at contrib/ltree
> OB> http://www.sai.msu.su/~megera/postgres/gist/ltree
>
> OB>         Oleg
> OB> On Fri, 9 Jan 2004 Anton.Nikiforov@loteco.ru wrote:
>
> >> Hello everybody!
> >>
> >> Does someone know how to build hierarchical queries to the postgresql?
> >>
> >> I have a table with tree in it (id, parent)
> >> and need to find a way from any point of the tree to any other point.
> >> And i would like to have a list of all steps from point A to point B
> >> to make some changes on each step (this is required by the algorythm).
> >>
> >> Here is an example:
> >> treetable (where tree is stored):
> >> id        parent   data
> >> int4      int4     varchar(255)
> >> 0         0        root
> >> 1         0        root's chield 1
> >> 2         0        root's chield 2
> >> 3         1        root's chield 1 chield 1
> >> 4         1        root's chield 1 chield 2
> >> 5         2        root's chield 2 chield 1
> >> 6         2        root's chield 2 chield 2
> >>
> >> And i want to get something like this:
> >> start point "root's chield 2 chield 2"
> >> finish "root's chield 1 chield 1"
> >>
> >> And the result i need:
> >> id        parent   data
> >> 6         2        root's chield 2 chield 2
> >> 2         0        root's chield 2
> >> 0         0        root
> >> 1         0        root's chield 1
> >> 4         1        root's chield 1 chield 2
> >>
> >> i know that it is possible in Oracle but what about postgres?
> >>
> >> Best regards,
> >> Anton Nikiforov
> >>
> >>
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>
> OB>         Regards,
> OB>                 Oleg
> OB> _____________________________________________________________
> OB> Oleg Bartunov, sci.researcher, hostmaster of AstroNet,
> OB> Sternberg Astronomical Institute, Moscow University (Russia)
> OB> Internet: oleg@sai.msu.su, http://www.sai.msu.su/~megera/
> OB> phone: +007(095)939-16-83, +007(095)939-23-83
>
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    Regards,
        Oleg
_____________________________________________________________
Oleg Bartunov, sci.researcher, hostmaster of AstroNet,
Sternberg Astronomical Institute, Moscow University (Russia)
Internet: oleg@sai.msu.su, http://www.sai.msu.su/~megera/
phone: +007(095)939-16-83, +007(095)939-23-83