On 8/7/07, Greg Sabino Mullane <[EMAIL PROTECTED]> wrote:
>
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> > As someone who just joined the mailing list, how do I look at the
> > subversion code?
>
> svn co http://svn.perl.org/modules/DBD-Pg/trunk dbdpg
Thank you.
Will this version remove the need for the second parameter to
pg_getline? If so, then that should be documented. I didn't install
so I can't test, but I'll note that with older versions of DBD::Pg
copying the code for pg_getline can result in undefined warnings. I
eliminated that by making sure that the variable passed in is defined.
Is this warning fixed in this version, or is that still bad?
I also think the cursor documentation could benefit from an example
showing how to use cursors. Here is a patch adding that.
Cheers,
Ben
--- Pg.pm.bak 2007-08-07 09:34:33.000000000 -0700
+++ Pg.pm 2007-08-07 10:03:29.000000000 -0700
@@ -3401,14 +3401,31 @@
=head2 Cursors
-Although PostgreSQL has a cursor concept, it has not been used in the current
+Although PostgreSQL supports cursors, they have not been used in the current
implementation. Cursors in PostgreSQL can only be used inside a transaction
block. Because only one transaction block at a time is allowed, this would
have implied the restriction not to use any nested C<SELECT> statements. Hence
the C<execute> method fetches all data at once into data structures located in
-the front-end application. This approach must to be considered when selecting
+the front-end application. This fact must to be considered when selecting
large amounts of data!
+You can use cursors in your application, but you'll need to do a little
+work. First you must make sure that autocommit is off. Then declare your
+cursor. Now you are able to issue queries against the cursor, and select
+against your queries. This typically results in a double loop, like this:
+
+ $dbh->{AutoCommit} = 0;
+ $dbh->do("DECLARE csr CURSOR FOR $sql");
+ while (1) {
+ my $sth = $dbh->prepare("fetch 1000 from csr");
+ $sth->execute;
+ last if 0 == $sth->rows;
+
+ while (my $row = $sth->fetchrow_hashref) {
+ # Do something with the data.
+ }
+ }
+
=head2 Datatype bool
