Question

Sorry for my inaccurate syntax. New to this.

I need to select part numbers in three different groups.

A different qty for each group.

Each group individually sorted ABS desc.

my $fromrow = CGI::param('from');## vague but put here to show a sort of pagination  ## 
my $nextrow = CGI::param('next');
my $grabpartnumbers = $hookup->prepare(qq{
   SELECT `New`,`Used`,`NOS`,`PartNum`,`Description`,`Price`
   FROM `Partstable`
   WHERE `instock` = ? AND `QTY` > ? AND `New` = ?
   ORDER BY ABS(PartNum) LIMIT ?,?});
$grabpartnumbers->execute('1','10','1',$fromrow,$nextrow);
while(@row = $grabpartnumbers->fetchrow_array()) {
#do stuff

Works fine, for one “column” eg “New”.
However, I want to display like:

New Stock
4 results

NOS
6 results

Used Stock
10 results

Additional problems will arise for me when one of the three “columns” have no more data to display. At that point, I just want to display the remaining result or nothing (not even the title header) if results = 0 for that cat.

Is this possible or do I need to prepare three different queries and possibly push each into their own arrays to decipher what to display in some loops?

This is VERY advanced for me so, please be verbose with examples. (dumb it down to my level of comprehension (-; )

Thanks..

EDIT:

My Partstable rows look like

   ID|PartNum|New|Used|NOS|Qty|instock|Description|Price
    1|132452 |1  |0   |0  | 24|y      |12ax7 yada |3.00

I want to display three “areas” on the same page by order of “importance”. “New” take priority.

New Stock 4 results

NOS 6 results

Used Stock 10 results

Answer 1

What you need to achieve is a little bit difficult to precisely comprehend, but it looks like you could potentially be just fine with a full-SQL solution (clever use of GROUP BY, etc.).

Regarding the current solution with Perl, and assuming I understand your example correctly, something like this would work as a starting point for you to play around and adapt to your actual dataset.

Warning: Code tested against syntax only!

my $fromrow = CGI::param('from');## vague but put here to show a sort of pagination  ## 
my $nextrow = CGI::param('next');

# Columns of interest, sorted by descending order of importance
my @interesting_columns = qw(
    New
    Used
    NOS
    PartNum
    Description
    Price
);

my $interesting_columns_expr = join(', ', map { $_ = "`$_`" } @interesting_columns);
my $grabpartnumbers = $hookup->prepare(qq{
    SELECT $interesting_columns_expr
    FROM `Partstable`
    WHERE `instock` = ? AND `QTY` > ? 
    ORDER BY ABS(PartNum) LIMIT ?,?
});
$grabpartnumbers->execute('1','10',$fromrow,$nextrow);

# Compute results
my %result_counter;
while ( my $row = $grabpartnumbers->fetchrow_hashref() ) {
    foreach my $column_name ( keys %$row ) {
        $result_counter{$column_name} += $row->{$column_name};
    }
}

# Display results
for my $column_name ( @interesting_columns ) {
    if (exists $result_counter{$column_name}) {
        print join( ':', $column_name, $result_counter{$column_name} );
    }
}