Thread

1. Nested tables

   Ferruccio Zamuner <solo3@mail.chierinet.it> — 1998-07-24T16:29:08Z

   Hi all,
   I'm relatively new to Postgres (V6.3.1), and I've come in trouble the
   following problem;
   I've defined the following:
   
   CREATE TABLE foo (
    x  int2
   );
   
   CREATE TABLE bar (
    y  foo,
    z  int
   );
   
   I read on some Postgres mailing digest that I had to put the OID of instance
   of foo into y field of bar.
   
   So I tried.
   
   The problem is that when I submit the following query:
   
      SELECT foo.x, bar.z WHERE foo.oid=bar.y;
   
   trying to catch int fields either from bar and from its instance of foo,
   Postgres replies that bar.y (of type foo) and foo.oid (of type oid) cannot be
   compared.
   I've also tried to cast them in many ways but the answer never changes!
   
   Any help would be greatly appreciated (I've completely missed the right way or
   just
   some detail?)
   
   Gianluca
   
   
   

2. Re: [GENERAL] Nested tables

   Matt McClure <matthew.mcclure@yale.edu> — 1998-07-24T19:38:22Z

   On Fri, 24 Jul 1998, Ferruccio Zamuner wrote:
   
   > CREATE TABLE foo (
   >  x  int2
   > );
   > 
   > CREATE TABLE bar (
   >  y  foo,
   >  z  int
   > );
   > 
   > I read on some Postgres mailing digest that I had to put the OID of instance
   > of foo into y field of bar.
   > 
   > So I tried.
   > 
   > The problem is that when I submit the following query:
   > 
   >    SELECT foo.x, bar.z WHERE foo.oid=bar.y;
   > 
   > trying to catch int fields either from bar and from its instance of foo,
   > Postgres replies that bar.y (of type foo) and foo.oid (of type oid) cannot be
   > compared.
   > I've also tried to cast them in many ways but the answer never changes!
   
   
   You could declare bar.y to be of type oid instead of type foo.