<?php
// Begin building the query.
  $query = db_select('watchdog', 'th')
    ->extend('PagerDefault')
    ->orderBy('wid')
    ->distinct()
    ->fields('th', array('variables', 'type', 'severity', 'message'))
    ->limit(2000);


// Fetch the result set.
  $result = $query  -> execute();


// Loop through each item and add to $row
  foreach ($result as $row) {
    blablabla($row);
  }
function

blablabla($row) {
  $severity = $row -> severity;
  $type = $row -> type;
  $message = $row -> message;
?>

%type: !message in %function (line %line of %file)...

%type: !message in %function (line %line of %file)...

blablabla($row) {
    $variables = unserialize($row->variables); // un serialize variables
    $message = t($row->message, array(
        'type'    => $row->type,
        'severity'=> $row->severity,
        // replace the rest of the variables
    ));