my $dbh     = database->connect_mysql();
my $sql     = "select * FROM mytable 
               WHERE date < DATE_ADD(NOW(), INTERVAL -30 DAY)";
my $records = $dbh->selectall_arrayref( $sql, { Slice => {} } );
foreach my $record ( @$records ) {
  my $user = $record->{user};
  my $id   = $record->{id};
  print "Data Test: $user - $id<br>";
}
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Check out the 'You may often want to fetch an array of rows where each row is stored as a hash' section of the DBI documentation.