my ($query) = our $connect->prepare("SELECT * FROM TableName");
  $query->execute();
  my $data = $query->fetchall_arrayref();
  $query->finish;

  foreach $data ( @$data) {

    my %row_data;  # get a fresh hash for the row data

foreach my $data_item (@$data) {

    $row_data{NAMEOFSQLCOLUMN} = "$data_item"; # How do I get the name of the SQL column that the data_item belong to?

    }

    }
    push(@loop_data, \%row_data);
  }