Vasyl Yaremchuk

How to Create Content Type in Drupal 7 Programmatically

Please, take a look on node_example module (http://drupal.org/project/examples)
There is a good example in this module, but I'm try to stop only on simple content type adding without any fields as extensions.

The code that will be created new content type we should add into .install file.

Lets add hook_install():

<?php
function your_module_name_install() {
  // use get_t() to get the name of our localization function for translation
  // during install, when t() is not available.
  $t = get_t();


  // Define the node type.
  $node_example = array(
    'type' => 'node_example',
    'name' => $t('Example Node'),
    'base' => 'node_content',
    'description' => $t('This is an example node type with a few fields.'),
    'body_label' => $t('Example Description')
  );


  // Complete the node type definition by setting any defaults not explicitly
  // declared above.
  // http://api.drupal.org/api/function/node_type_set_defaults/7
  $content_type = node_type_set_defaults($node_example);
  node_add_body_field($content_type);


  // Save the content type
  node_type_save($content_type);


?>

We should not add 
    node_types_rebuild();
    menu_rebuild();
in the code of your_module_name_install() because rebuild will perfome automatically.

According to the rules of good Drupal code, we should to make drupal message and write this event to the log:

<?php
function your_module_name_install() {
  $t = get_t();
  $node_example = array(
    'type' => 'node_example',
    'name' => $t('Example Node'),
    'base' => 'node_content',
    'description' => $t('This is an example node type with a few fields.'),
    'body_label' => $t('Example Description')
  );
  $content_type = node_type_set_defaults($node_example);
  node_add_body_field($content_type);
// Check if we create content type or update.
  $status = node_type_save($content_type);
// Replacement rule for the messages.
  $t_args = array('%name' => $content_type->name);
  if ($status == SAVED_UPDATED) { // update case
    drupal_set_message($t('The content type %name has been updated.', $t_args));
  } 
  elseif ($status == SAVED_NEW) { // create case
    drupal_set_message($t('The content type %name has been added.', $t_args));
    watchdog('node', 'Added content type %name.', $t_args, WATCHDOG_NOTICE, l($t('view'), 'admin/structure/types')); 
  }


?>

Ok, and we also should provide hook_uninstall() to remove our content type:

<?php
function your_module_name_uninstall() {
  // Gather all the example content that might have been created while this
  // module was enabled.  Simple selects still use db_query().
  // http://api.drupal.org/api/function/db_query/7
  $sql = 'SELECT nid FROM {node} n WHERE n.type = :type';
  $result = db_query($sql, array(':type' => 'node_example'));
  $nids = array();
  foreach ($result as $row) {
    $nids[] = $row->nid;
  }
  // Delete all the nodes at once
  // http://api.drupal.org/api/function/node_delete_multiple/7
  node_delete_multiple($nids);
  // Delete our content type
  // http://api.drupal.org/api/function/node_type_delete/7
  node_type_delete('node_example');


?>

I should mention that if we will not delete all nodes of such content type the function node_type_delete() will not run.

See also How to transfer the content type settings by Features.