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

I get this error with my code
Use of uninitialized value in concatenation (.) at D:\begperl\build_de_sample.pl line 83.

Now that line is --- push @list3, "$id1\t$text\n";

After playing around with the code I know the problem is with $text, but I don't understand the problem b\c I declare $text.

Your wisdom is appreciated. 
# ***********
# CDS MVOCXX
# ***********
my ($sqlquery3, @list3);
# PREPARE SQLQUERY3 CDS_MVOCXX**********************************
$sqlquery3=$CDS->prepare("
SELECT distinct cds_mvocxx.id, cds_mvocxx.text
    FROM cds_mvocxx, (
        SELECT cds_mspecxx.* 
            FROM cds_mspecxx, (
                SELECT prodid
                    FROM cds_prod
                    WHERE catid = 'AC')vt1
            WHERE cds_mspecxx.prodid = vt1.prodid)vt2
    WHERE id = vt2.hdrid or
    id = vt2.bodyid");
# RUN SQLQUERY3 CDS_MVOCXX***********************************    
$sqlquery3->execute() || die "couldn't execute query: $DBI::errstr\n";
print "run\n";
while (( my $id1, my $text) = $sqlquery3->fetchrow_array) 
    {
        push @list3, "$id1\t$text\n";
    }    
# WRITE CDS_MVOCXX to a file***************************************   
+      
open cds_mvocxx, "> c:/splitcat/components/mvocxx.txt" or die "i'm dyi
+ng can't open log file";
print cds_mvocxx @list3;
$sqlquery3 ->finish();
close cds_mvocxx;

[download]

Replies are listed 'Best First'.
Re: wise ones, your help is needed
by japhy (Canon) on May 02, 2001 at 20:47 UTC
[reply]
[d/l]
      works like a charm 
      while (( my $id1, my $text) = $sqlquery3->fetchrow_array) 
    {    $text = '' if not defined $text;
        push @list3, "$id1\t$text\n";
    }

      [download]
[reply]
[d/l]
        The "more standard" (?) way of writing that would be: 
        while (my ($id1, $text) = ...) { ... }

        [download]
        That is, declaring both variables at the same time. It looks nicer that way, I feel.

        japhy -- Perl and Regex Hacker
[reply]
[d/l]
      Why use negation when there is always the handy-dandy unless loop? This works as well.

      $text = '' unless defined $text;

      [download]
      And it is much clearer to read (at least to me) :)

      Tiptoeing up to a Perl hacker.
      Dave AKA damian
[reply]
[d/l]
        I didn't use "unless" there, since "if not" is the same length, and it didn't hinder comprehension. (Not to mention 'unless' becomes 'if not' at compile-time, anyway.)

        japhy -- Perl and Regex Hacker
[reply]
Re: wise ones, your help is needed
by Jouke (Curate) on May 02, 2001 at 20:53 UTC
    Hi,
    In your line:
    while (( my $id1, my $text) = $sqlquery3->fetchrow_array)
    You do not check if the query indeed returns a second value for $text. You should check if the variables get values before you use them.

    hth,

    Jouke Visser, Perl 'Adept'
[reply]
[d/l]

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