By xjm on
Change record status: 
Published (View all published change records)
Project: 
Drupal core
Introduced in branch: 
8.x
Issue links: 
https://www.drupal.org/node/2168011
https://www.drupal.org/node/2190695
Description: 

Drupal 8 no longer supports upgrading data from Drupal 7 using the database update system (update.php). Instead, Drupal core and contributed modules will provide data migration from Drupal 6 and 7 installations to Drupal 8 installations using a Drupal 8 data migration feature based on the Migrate module.

Minor and patch version upgrades will still use update.php, including (for example):

  • 8.0.0 to 8.0.1
  • 8.0.7 to 8.1.0
  • 8.x-1.0 to 8.x-1.1

Impacts on contributed module developers

Use the migration API instead of hook_update_N() to migrate data to Drupal 8

To upgrade your module's data to Drupal 8 from Drupal 6 or 7, use the Drupal 8 Migration API to give module users a way to migrate the data from a Drupal 6 or 7 site to a newly architected Drupal 8 site. (See https://drupal.org/node/2141805 for an example.) hook_update_N() should only be used for minor version updates (for example, a schema change introduced in 8.x-1.1).

Schema version 8000 is reserved for the minimum core schema version

Previously, hook_update_N000() was used to denote the hook that provided an upgrade from Drupal N - 1 to Drupal N. Since this is no longer supported, the schema version 8000 is now reserved for the minimum installed version of core modules with no updates.

  • The constant SCHEMA_INSTALLED is replaced with \Drupal::CORE_MINIMUM_SCHEMA_VERSION, which will have a value of 8000 for Drupal 8, 9000 for Drupal 9, etc.
  • Core modules should begin numbering their minor version update hooks with hook_update_8001().
  • Contributed modules should begin numbering their minor version update hooks with (e.g.) hook_update_8100() for the 8.x-1.x branch of the module. (See the hook_update_N() API documentation for more information.)
  • Declaring hook_update_8000() in a module is not allowed and will prevent updates for being run for that module.

Impacts on site owners

It is no longer supported to upgrade a Drupal 7 site to Drupal 8 directly. If you attempt to upgrade a site with a Drupal 7 database to Drupal 8, you will receive a requirements error. To upgrade to Drupal 8, install and configure a new Drupal 8 site mirroring your Drupal 7 site, and then migrate your data using the new Migrate in core functionality once it is complete in an upcoming Drupal 8 release.

Core API changes

Several update helper functions are removed.

  • update_add_uuids()
  • update_add_cache_columns()
  • function update_prepare_stored_includes()
  • function update_prepare_d8_bootstrap()
  • function update_prepare_d8_language()
  • function update_fix_d8_requirements()
  • function update_variable_get()
  • function update_variable_set()
  • function update_variable_del()
  • function update_variables_to_config()
  • function update_install_default_config()
  • function update_variables_to_state()
  • function _update_8000_entity_get_display()
  • function _update_8000_entity_get_form_display()
  • function _update_8003_field_create_field()
  • function _update_8003_field_create_instance()
  • function _update_8006_field_write_data_sql()
  • function _update_7000_node_get_types()

Additionally, update_extra_requirements() is replaced with specific functions update_system_schema_requirements() and update_settings_file_requirements().

A couple constants are altered as well.

  • Removed
    • const SCHEMA_INSTALLED = 0;
    • const REQUIRED_D7_SCHEMA_VERSION = '7069';
  • Added
    • const \Drupal::CORE_MINIMUM_SCHEMA_VERSION = 8000;
Impacts: 
Site builders, administrators, editors
Module developers