> It seems to me this is a simple problem, but the solution eludes me.
>
> I have a table:
>
> bank_account (
> transaction_id int not null serial,
> customer_id int not null references customer(id),
> ts timestamp not null default now(),
> amount float not null,
> balance float not null,
> primary key(transaction_id)
> )
>
> I need to get the most recent transaction for each customer. I need only
> the transaction ID, but the entire row would be best.
For the sake of being explicit, change your table definition (though
what you have above is a-okay and works):
CREATE SEQUENCE transaction_id_seq;
CREATE TABLE bank_account ( transaction_id int not null DEFAULT NEXTVAL('transaction_id_seq'::TEXT), customer_id int
notnull references customer(id), ts timestamp not null default now(), amount float not null, balance float not null,
primarykey(transaction_id)
);
Once you insert a value into the bank_account table, SELECT
CURRVAL('transaction_id_seq') will be what you're looking for. Read
up on CURRVAL() at:
http://www.postgresql.org/docs/view.php?version=7.3&idoc=1&file=functions-sequence.html
-sc
--
Sean Chittenden