Re: Howto retrieve all the grandchildren of all the

On Fri, 2002-01-25 at 15:48, Jeffrey W. Baker wrote:
> 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

Oops, gratuitous use of join:

SELECT table3.*
FROM table3
, table2
WHERE table3.parent = table2.id
AND table2.parent = 123456

-jwb