Can I get that coloumn names from db???

You can get table and column names from the db using queries: 

my (@tables, %map);
my $q = $dbh->prepare("show tables");
$q->execute or die "Error listing tables";
        
while ( my ($table) = $q->fetchrow_array ) {
    push @tables, $table;
}
$q->finish;
for my $table (@tables) {
    $q = $dbh->prepare("describe $table");
    $q->execute or die "Error describing table $table";

    while ( my $hr = $q->fetchrow_hashref ) { 
        push @{ $map{$table} }, $hr->{Field};
    }
    $q->finish;
}

[download]

Now you have a hash %map keyed on table names, whose values are anonymous arrays containing column names. Use this array to build your query:

my $table_name = "CDR";
my $sql = "select ".join ",", map { "sum($_)" } @{$map{$table_name}};
$sql .= " from $table_name where Date = ? and Hour like ?";

[download]
perl -le'print map{pack c,($-++?1:13)+ord}split//,ESEL'

In reply to Re^9: using system command in regex by shmem
in thread using system command in regex by ravi45722

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