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RE: Really stuck: DBI, mysqlPP.

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Dan Muey
December 31, 2002 06:25
RE: Really stuck: DBI, mysqlPP.
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I have this in a working script runs no problem at all. 
Mysql version 3.26 I think. 
Do you verify that that the query was executed?
If the query gets bad then it will never get to your while loop.
You could use DBI->trace to see what's going on.

	$query = "DESCRIBE $existing_table_name";

	my $sth = $dbh->prepare($query) or die "Can not prepare $query :" . $dbh->errstr ."\n";
	$sth->execute or die "Can not execute $query :" . $dbh->errstr . "\n";

	my $row;
	while(@row = $sth->fetchrow_array) {

		print "$row[0] \n";



-----Original Message-----
From: Craig Williams [] 
Sent: Monday, December 30, 2002 6:49 PM
Subject: Really stuck: DBI, mysqlPP.

Ok, firstly - I don't believe this is a mysql issue as I have a working server which I can prove and the fact I've just learnt Perl was my reason for posting here, maybe I've screwed up the syntax.

I just installed the modules for DBI and MySQL and they seem to work great except for one aspect. Getting column names.

Code example; (code sits in a debug sub)

my $sq = $myconn->prepare("show columns from as_codes;"); $sq->execute(); while (@tmp = $sq->fetchrow_array()) { print $tmp[0], "\n"; }

$myconn is a working connection: the select statements work great.

The above always produces nothing, the while loop never runs. I've also tried the "describe" sql statement but I get the same results. The table as_codes has about 12 columns. I even tried the DBI, {NAME} option but got no columns returned.

If I go into mysql admin and type the above statement then it works. Also, if I put the above code into a loop and say force it to perform the operation 10 times, it will work for at least 1 of them.

Is this a bug ? Where can I look next ?



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