CODEWITHSUNDEEP
sqlperl
chaw359
chaw359

Reputation: 13

Use of uninitialized value in concatenation (.) or string at

I've this error:

Use of uninitialized value in concatenation (.) or string at...

This is my code:

$queryH= $dbh->prepare($query);
$queryH->execute();
my $i=0;
my $result;
while (@data = $queryH->fetchrow_array()) 
{
    $result=$data[$i];
    if ($result)
    {
        print "$result \n";
    }
    else
    {
        print "Records Not Found!\n";
        last;
    }
    print "\n";
    $i++;
}
print "\n\n";
$queryH->finish();
$dbh->disconnect();

What error is there in my code?

The error is on the line:

$result=$data[$i];

Upvotes: 0

Views: 2247

Answers (1)

simbabque
simbabque

Reputation: 54381

You are starting out with $i=0 and you increment it with each pass of the while loop. You look at $data[$i] once for each line of database result. So for the first row, you look at $data[0]. For the second row of data, you look at $data[1] and so on. At some point, your $i (which is effectively a rowcount starting at zero) will be higher than the number of fields per row. That produces the error message.

If you put in a print "$i\n" in the beginning of the while block you will see what I am talking about.

Upvotes: 1

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