Database Data Page

[artist]

Dear Monks
Here is my code-cut.

my $result = Database->get_results($query);
Display->results($result);

and package Display uses HTML::Template to display the $result. It works fine currently. It displays 5000+ records.

Q: How do I use HTML::Pager or another module such that I can display data page by page, may be 100 at a time.

Thank you,
artist

[cleverett]

There's major issues with HTML::Pager I see up front: it wants the whole data set up front, and it uses CGI.pm, not quite the thing when you have HTML::Template, IMO.

Since retrieving the entire data set every time through is grossly inefficient, you likely will end up doing one or both of two things: retrieving just the rows you need or caching the results someplace.

Many dialects of SQL will let you specify the rows you need. For instance Mysql has a LIMIT clause:

SELECT * FROM bannerlog.log LIMIT 100, 100;

which says return only the rows starting at the 101st row and going 100 rows from there.

If we were saving state using HTML form variables and using CGI::Request to fetch form parameters (using mod_perl, I'd use Apache::Request) our code would then end up something like:

use CGI::Request;
my $req = new CGI::Request;
my $rows_per_page = 100;
my ($first_row, $command) = map { $req->param($_) } 
                                qw/first_row command/;
if ($command eq 'previous_page') {
  $first_row -= $rows_per_page;
  $first_row = 0 if $first_row < 0;
} elsif ($command eq 'next_page') {
  $first_row += $rows_per_page;
}

my $result = Database->get_results($query, $first_row);
Display->results($result, $first_row);

good luck!

[little]

what about using LIMIT as a native SQL language construct?
SELECT * FROM tableName LIMIT 0, 10
or in another way:
SELECT $whatever and $whomever FROM $sometable LIMIT $minDisplaySetOff, $maxDisplayRowsPerPage
actually it should read $maxDisplayRowsPerResultSet

Have a nice day
All decision is left to your taste