Theming a custom data table from php code text format with Drupal 7

Question

I have a working block of php code that runs inside a Drupal 7 Page:

<?php
$my_database= array(
  'database' => 'mydb',
  'username' => 'xxxxxx', // assuming this is necessary
  'password' => 'xxxxxx', // assuming this is necessary
  'host' => 'localhost', // assumes localhost
  'driver' => 'mysql', // replace with your database driver
);
Database::addConnectionInfo('database_db', 'default', $my_database);
db_set_active('database_db');
$sql = "SELECT tcol1, tcol2 FROM mytable LIMIT 10";

$result = db_query($sql);
$header = array('Col1', 'Col2');
$rows = array();
if ($result) {
  while ($row = $result->fetchAssoc()) {
    $row= array($row['tcol1'],$row['tcol2']);
  $rows[] = $row;
  }
}
db_set_active();
print_r($rows);
$output= theme('table', $header, $rows);
?>

This piece of code works fine and print_r() prints all the data I asked for. The odd thing is that the theming fails totally, showing nothing. I have done some experimentation:

    $output= theme('table', $header, $rows);
    echo theme('table', $header, $rows);
    print theme('table', $header, $rows);

but all of them fail, showing nothing or disrupting drupal globally. How can I show my data in a nice table? I want to avoid writing html code and instead rely on Drupal theming.

Answer 1

The format of arguments to theme functions changed in Drupal 7, instead of

$output = theme('table', $header, $rows);

you need to use

$output = theme('table', array('header' => $header, 'rows' => $rows));

or, using a render array,

$build = array(
  '#theme' => 'table',
  '#header' => $header,
  '#rows' => $rows,
);
$output = drupal_render($build);