| From: | "Jeffrey W(dot) Baker" <jwbaker(at)acm(dot)org> |
|---|---|
| To: | Joost Kraaijeveld <J(dot)Kraaijeveld(at)Askesis(dot)nl> |
| Cc: | Postgres general mailing list <pgsql-general(at)postgresql(dot)org> |
| Subject: | Re: Howto retrieve all the grandchildren of all the |
| Date: | 2002-01-25 23:48:20 |
| Message-ID: | 1012002501.2700.15.camel@heat |
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| Lists: | pgsql-general |
On Fri, 2002-01-25 at 15:13, Joost Kraaijeveld wrote:
> I have three tables. Table 1 contains the root of a tree. Table 2 contains
> the children of table 1 (column acting as foreign key). Table 3 contains the
> children of table 2 (column acting as foreign key). Basically it contains a
> three level n-ary tree.
>
> Is it possible to retrieve the grandchildren if I have the primary key of a
> record in table 1, assuming that each table has a primary key and an
> appropriate foreign key, and if so, what should be the SQL syntax to do so?
SELECT table3.*
FROM table3
, table2
, table1
WHERE table3.parent = table2.id
AND table2.parent = table1.id
AND table1.id = 123456
-jwb
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