Re^2: perl and psql

[gogoglou]

thanks for your reply. I am really new in perl soany help is usefull. I get a small error message though. first I create at he top of the script my $table which has a start and an end position, but then when I replace the print with the example you gave me I get an error that says that my clusters requires explicit package name. I don't really understand why this happens in this case, since the clusters have been declared. Any ideas would be really usefull. Thanks

[bv]

There was a bug in the code that was posted as a reply. I don't think Xilman intended that code to be blindly copy-and-pasted, but here's what's probably going on:

# This should not have the '$dbh->' at the beginning, but the real iss
+ue is
# $cluster here is a scalar, but
foreach my $cluster (@clusters) {
# here, they are being treated as arrays (if they were interpolated as
+ written.
# $dbh->do ("INSERT INTO $table (start, end) VALUES (cluster[0], clust
+er[1]);");
# a better approach, if your DBI module supports placeholders:
$dbh->do ("INSERT INTO $table (start, end) VALUES (?,?);", @{$cluster}
+)
# or even: $dbh->do ("INSERT INTO $table (start, end) VALUES (?,?);", 
+$cluster->[0], $cluster->[1])
}

Again, this is untested code, and may not work as advertised. If the -> and @{} are confusing you, check out perlreftut for more info on references.

[almut]

$dbh->do ("INSERT INTO $table (start, end) VALUES (?,?);", @{$cluster})

When you use do with placeholders and bind values, you also need to specify the \%attr hashref (for syntactical reasons, because the synopsis is $dbh->do($statement, \%attr, @bind_values)).  You may use undef if you don't have any attributes.

$dbh->do ("INSERT INTO $table (start, end) VALUES (?,?)", undef, @$clu
+ster)

[Xilman]

Thank you. It was an unfortunate cut&paste error on my part.

I'm well aware, of course, that place holders are a Good Idea(tm). The original Perl script from which I made the c&p used them but I removed them from the posted snippet to simplify it.

As I said originally, the OP should take my fragment as a hint for a learning exercise and not as a complete answer.

Paul