Date: Sun, 19 Jan 2003 15:17:14 +0100
From: "Jeroen T. Vermeulen" <jtv@xs4all.nl>
To: Key88 SF <key88sf@hotmail.com>
Cc: pgsql-interfaces@postgresql.org
Subject: Re: libpqxx: Cursors needed??!
Message-ID: <20030119141713.GC84000@xs4all.nl>
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On Wed, Jan 15, 2003 at 10:51:22PM +0000, Key88 SF wrote:
> 
> It's not clear to me when to use the Cursor class, if at all. Transactions 
> seem to execute fine and I get valid Result classes back without using 
> cursors. 

There's no special reason why you should use Cursor to retrieve
results--you can always just call TransactionItf::Exec() and get
Results from that.  Use Cursor only when you want to create an
SQL cursor.

 
> Many of the sample programs don't use them either.
 
The sample programs were mostly written in the order in which they're
numbered, so some of them predate cursors.


> Are cursors needed at all??

No.  It's a convenience class; you can always just execute the
cursor-related commands by hand.  The wrapper class just gives you
conveniences like additional compiler checking, more specific error
messages, more user-friendly syntax, and absolute positioning.  The
latter may be a little harder to do for yourself than it seems,
because of the way postgres returns tuple counts when moving or
fetching with a cursor.


Jeroen