From: fastjack@... (Martin Maciaszek)
Date: 2002-02-05T21:40:22+09:00
Subject: some dbi questions (probably postres specific)

I'm playing around with dbi and postgres. After a while two problems remained
that I couldn't solve so far.

1. after doing a DBI::DatabaseHandle.select_all I get an array containing
   the result. In php I could also get the field names for the result. (
   using pg_fieldname($result, $index)) Is there something similar in
   ruby's dbi?

2. another problem arose when I tried wrapping objects around tables. I
   created a table with the following structure:
 Column|  Type   |                     Modifiers                        
-------+---------+------------------------------------------------------
 id    | integer | not null default nextval('"test_table_id_seq"'::text)
 name  | text    | 
 phone | text    | 

   now I insert some data into the table with the following code:
   aConnection.execute "insert into test_table (name, phone) values
                        ('foo', '42');"

   the id field is also my primary key, so I would like to know which id
   got assigned to the values I just inserted. I've been told that perl-dbi
   and php have some way to get some kind of handle to the last insert.
   I came up with two solutions that both look like ugly hacks. 1. I could
   try to read test_table_id_seq so I would know the last id. This works
   unless somebody else inserts another record in the mean time. 2. I could
   ask for exactly the same velues I just inserted into the database. This
   one looks better but could fail horribly if there is already an entry
   for "foo" with phone number "42" but a different id.

I hope somebody can share his thoughts with me.

Cheers
Martin