Consensus Enterprises: Drupal 8 hook_update() Tricks

In Drupal 7, hook_update()/hook_install() were well-established mechanisms for manipulating the database when installing a new site or updating an existing one. Most of these routines ended up directly running SQL against the database, where all kinds of state, configuration, and content data lived. This worked reasonably well if you were careful and had a good knowledge of how the database schema fit together, but things tended to get complicated.