Re: Howto retrieve all the grandchildren of all the
| От | Jeffrey W. Baker |
|---|---|
| Тема | Re: Howto retrieve all the grandchildren of all the |
| Дата | |
| Msg-id | 1012002501.2700.15.camel@heat обсуждение исходный текст |
| Ответ на | Howto retrieve all the grandchildren of all the children (Joost Kraaijeveld <J.Kraaijeveld@Askesis.nl>) |
| Ответы |
Re: Howto retrieve all the grandchildren of all the
|
| Список | 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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