#!/usr/bin/perl -w
use strict;
use warnings;

my @data_list = (
    {key => 'date', value => ''},
    {key => 'correct', value => 'Article_text1'},
    {key => 'correct', value => 'Article_text2'},
    {key => 'date', value => '2009-01-01'},
    {key => 'date', value => '2009-01-02'},
    {key => 'date', value => ''}
);

my ($correction, $date);
foreach my $data_pair(@data_list) {

$correction = $data_pair->{value}
    if exists $data_pair->{value} and    # could be undef
      defined $data_pair->{value} and    # at least ""
      length $data_pair->{value}  and    # has length
      $data_pair->{value}         and    #  has true value
      $data_pair->{key} eq 'correct';


$date = $data_pair->{value}
    if exists $data_pair->{value} and    # could be undef
      defined $data_pair->{value} and    # at least ""
      length $data_pair->{value}  and    # has length
      $data_pair->{value}         and    #  has true value
      $data_pair->{key} eq 'date';

    if($correction && $date) {

my $sql .= "
INSERT IGNORE INTO table SET
       text = '".$correction."',
       date='".$date."'";
        print $sql;
        # Reset for the next loop
        ($correction, $date) = (undef, undef);
    }
}

##</code><code>##

INSERT IGNORE INTO table SET
       text = 'Article_text2',
       date='2009-01-01'

##</code><code>##

INSERT IGNORE INTO table SET
       text = 'Article_text1',
       date='2009-01-01'
INSERT IGNORE INTO table SET
       text = 'Article_text2',
       date='2009-01-02'