module_hide.install

<?php

/**
 * Implements hook_install(). Add "hidden" field to the system table schema.
 */
function module_hide_install() {
  $ret = array();

  // Define the field that I am adding to the system table
  $field = array(
    'type' => 'int',
    'not null' => TRUE,
    'default' => 0,
  );

  // Add this field
  db_add_field($ret, 'system', 'hidden', $field);
}

/**
 * Implements hook_schema_alter().
 */
//function module_hide_schema_alter() {
  //@TODO Figure out if I need to alter the schema to account for the column
  // that I added to the db. The comment code below may or may not be working.
  // $schema['system'] = array(
  //   'fields' => array(
  // 	  'hidden' => array(
  // 	    'description' => 'Boolean indicating whether or not this module or theme should be hidden.',
  // 	    'type' => 'int',
  // 	    'not null' => TRUE,
  // 	    'default' => 0),
  //   ),
  // );
//}

/**
 * Implements hook_uninstall().
 */
function module_hide_uninstall() {
	  $ret = array();
	  db_drop_field($ret, 'system', 'hidden');
}