Delete nodes by type in /devel/php

gistfile1.txt

ignore_user_abort(true);
ini_set('max_execution_time', 600);
set_time_limit(0);

$node_type = 'story';
  
  //fetch the nodes we want to delete
  $result =  db_query('SELECT n.nid FROM {node} n WHERE n.type = :node_type', array(':node_type' => $node_type));
  foreach( $result as $row ){    
    node_delete($row->nid);
    $deleted_count+=1;
  }
  //simple debug message so we can see what had been deleted.
  drupal_set_message("$deleted_count nodes have been deleted");