<?php
if (arg(0) == 'node' && is_numeric(arg(1)) && is_null(arg(2))) {
  $nid = (int)arg(1);
  $terms = taxonomy_node_get_terms($nid);
  $output = "<ul>";
  foreach($terms as $term){
    $sql = "SELECT n.title, n.nid FROM {node} n INNER JOIN {term_node} tn ON n.nid = tn.nid WHERE tn.tid = $term->tid AND n.nid != $nid LIMIT 5";  
    $result = db_query(db_rewrite_sql($sql));
    if (db_num_rows($result)) {
      $output .="<li>$term->name</li><ul>";
      while ($anode = db_fetch_object($result)) {
        $output .= "<li>".l($anode->title, "node/$anode->nid")."</li>";
      }  
      $output.="</ul>";
    }
  }
  $output .= "</ul>";
  return $output;
}
?>

Use the code below to build a custom block that shows the related nodes to the current node by taxonomy term. For example: If the current node in display has a taxonomy term "fish", a bunch of links that link to nodes that have the "fish" term is to be shown in a block on the page.

Related nodes to the current node by taxonomy term (1)

module, drupal

PHP