DBX::Recordset - abstracts a DBX query result

DBX documentation Contained in the DBX distribution.

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NAME

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DBX::Recordset - abstracts a DBX query result

SYNOPSIS

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  use DBX;

  $conn = DBX->mysql("database=test;host=localhost;", "", "");

  $rs = $conn->query("SELECT * FROM test");

  while($rs)
  {
	print $rs->field("client") . "\n";
	$rs->field("client", "test");
	$rs->move_next;
  }

DESCRIPTION

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DBX::Recordset is the heart of the DBX and provides most of its additional functionality. Recordsets are returned by the query method of a DBX::Connection object.

Recordsets support simple forward-only cursors (at the moment) and allow you to easily retrieve and/or modify fields.

eof

Returns a value indicating whether or not the recordset has reached its end. DBX::Recordset overrides the numification operator so that if($rs) is equivalent to if($rs-eof)>.

field(NAME [, VALUE])

The field subroutine will return the value of the field named NAME. If a second parameter is passed, then the field with that name will be set to that value. Note that changes made with the field function don't take effect until update() is called or the cursor moves.

move_first

Moves the recordset's cursor to the beginning of the set. Works only for random-access cursors. NOT YET IMPLEMENTED.

move_prev

Moves the recordset's cursor to the previous record. Works only for random-access cursors. NOT YET IMPLEMENTED.

move_next

Moves the recordset's cursor to the next record. Works for random-access and forward-only cursors. If the recordset has reached its end, the EOF flag will be set.

move_last

Moves the recordset's cursor to the end of the set. Works only for random-access cursors. NOT YET IMPLEMENTED.

update

Saves changes to the current record. update is automatically called when the cursor is moved.

DEPENDENCIES

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Requires DBX and all of its dependencies

SEE ALSO

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DBI, DBX, DBX::Connection

AUTHOR

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Bill Atkins, <dbxNOSPAM@batkins.com>

COPYRIGHT AND LICENSE

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Copyright 2003 by Bill Atkins

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

DBX documentation Contained in the DBX distribution. 
package DBX::Recordset;

use DBI;
use DBX::Constants;

use overload "0+" => \&as_num;

use strict;
use warnings;

our $VERSION = '0.1';

sub new
{
	my ($class, $dbh, $sth, $how, $query) = @_;
	my ($table) = ($query =~ / from (.*)/i);
	my $self = { sth => $sth, how => $how, table => $table, dbh => $dbh };

	bless $self, $class;
	$self->fetch;
	return $self;
}

sub move_first
{
	my ($self) = @_;
	$self->clear;
	die "Selected cursor cannot move_first" if $self->{how} !=  DBX_CURSOR_RANDOM;
}

sub move_last
{
	my ($self) = @_;
	$self->clear;
	die "Selected cursor cannot move_last" if $self->{how} !=  DBX_CURSOR_RANDOM;
}

sub move_next
{
	my ($self) = @_;

	$self->update;
	$self->fetch;
}

sub fetch
{
	my ($self) = @_;
	$self->clear;
	$self->{cur_rec} = $self->{sth}->fetchrow_hashref;

	if(!$self->{cur_rec})
	{
		$self->{eof} = 1;
	}
}

sub move_prev
{
	my ($self) = @_;
	$self->clear;
	die "Selected cursor cannot move_prev" if $self->{how} !=  DBX_CURSOR_RANDOM;
}

sub eof
{
	my ($self) = @_;
	$self->{eof};
}

sub clear
{
	my ($self) = @_;

	$self->{dirty} = 0;
	$self->{changed} = {};
}

sub field
{
	my ($self, $field, $value) = @_;
	if(not defined $value)
	{
		my $value = $self->{cur_rec}->{$field};
		die "No such field" unless $value;
		return $value;
	}
	else
	{
		$self->{dirty} = 1;
		$self->{changed}->{$field} = $value;
		return $value;
	}
}

sub as_num
{
	my ($self) = @_;

	return !$self->{eof};
}

sub update
{
	my ($self) = @_;
	return unless $self->{dirty};

	my %changed = %{$self->{changed}};
	my %old = %{$self->{cur_rec}};

	my $sql = "UPDATE $self->{table} SET ";

	for(keys(%changed))
	{
		$sql .= "$_ = '$changed{$_}', ";
	}

	$sql =~ s/, $//;
	$sql .= "WHERE ";

	for(keys(%old))
	{
		$sql .= "$_ = '$old{$_}' AND ";
	}

	$sql =~ s/ AND $/\;/;

	$self->{dbh}->do($sql) or die $!;
}

1;

__END__