DBI and the hell it has made my life...

coyotlgw has asked for the wisdom of the Perl Monks concerning the following question:

I am trying to call a simple line from a table with only two lines. This whole shippet seems to work until the bind line, where I see the error:

    Can't call method "bind_columns" without a package or object refer
+ence at /var/www/cgi-bin/noctracker.pl line 95.
[download]

The code snippet in question is:

    use DBI;
    $dbh = DBI->connect("DBI:mysql:gds:localhost", "tools", "meep") or
+ die  ("No love for the DBI connect");
    $sql = qq{ SELECT uname, fname, fgroup, dmod, accts FROM noctracke
+r WHERE uname = 'gwalker'} ;
    $sth = $dbh->do( $sql ) or die ("Could not select");

    my( $uname, $fname, $fgroup, $dmod, $accts );
    $sth->bind_columns( undef, \$uname, \$fname, \$fgroup, \$dmod, \$a
+ccts );  # this is line 95
[download]

Comment on DBI and the hell it has made my life... Select or Download Code

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Re: DBI and the hell it has made my life... by eric256 (Parson) on Aug 21, 2003 at 20:48 UTC
You are trying to assign `$sth` as a statement handle, but you can only do that when you `prepare` the statment first. A `prepare` call returns a statment handle,execute, then you bind your columns. Here is the code form bind_columns on the DBI page of CPAN `$dbh->{RaiseError} = 1; # do this, or check every call for errors $sth = $dbh->prepare(q{ SELECT region, sales FROM sales_by_region }) +; $sth->execute; my ($region, $sales); # Bind Perl variables to columns: $rv = $sth->bind_columns(\$region, \$sales); while ($sth->fetch) { print "$region: $sales\n"; }` [download] Notice how they first prepare,then execute,then bind, then fetch. Good luck! Updated: I confused bind_params and bind_colunms. thanks gmax for pointing out my mistake. ___________ Eric Hodges	[reply] [d/l] [select]
Re: DBI and the hell it has made my life... by princepawn (Parson) on Aug 21, 2003 at 20:56 UTC
Your first issue is that you did not `use strict`. Second, connect with `RaiseError` set to 1 so you can get rid of the `or die` in your code. Third, `do` returns the number of rows affected or undef, you need to use `execute` as the docs state: It should not be used for SELECT statements because it does not return a statement handle (so you can't fetch any data). Carter's compass: I know I'm on the right track when by deleting something, I'm adding functionality... download and use The Emacs Code Browser	[reply] [d/l] [select]
Re: DBI and the hell it has made my life... by lestrrat (Deacon) on Aug 21, 2003 at 20:49 UTC
Yes, the error is expected, and the behavior is correct. `do()` doesn't return a Statement Handle. Use `prepare()` instead	[reply] [d/l] [select]
Re: DBI and the hell it has made my life... by coyotlgw (Initiate) on Aug 21, 2003 at 21:08 UTC
Behold, the power of "RTFM"! Sorry, while you three were responding, I re-read the PerlDBI book's section on this and discovered that I could ont use do... had to use prepare and execute. Sorry about that...	[reply]