test1/public/drupal-8.3.1/modules/profile/profile.inst...

<?php

/**
 * @file
 * Install, update and uninstall functions for the profile module.
 */

/**
 * Uninstalls the langcode field from the profile entity.
 */
function profile_update_8001() {
  $definition = \Drupal::entityTypeManager()->getDefinition('profile');

  // Allow langcode field to be null.
  $schema = \Drupal::database()->schema();
  if ($schema->fieldExists($definition->getBaseTable(), 'langcode')) {
    $schema->changeField($definition->getBaseTable(), 'langcode', 'langcode', [
      'type' => 'varchar',
      'length' => 12,
      'not null' => FALSE,
    ]);

    // Set langcode field to null so it can be deleted.
    \Drupal::database()
      ->update($definition->getBaseTable())
      ->fields(['langcode' => NULL])
      ->execute();
  }

  $entity_definition_update = \Drupal::entityDefinitionUpdateManager();
  if ($storage_definition = $entity_definition_update->getFieldStorageDefinition('langcode', 'profile')) {
    $entity_definition_update->uninstallFieldStorageDefinition($storage_definition);
  }

  return t('Language code field uninstalled from profile entity.');
}