Remove field storage information when field data is purged.
Called from field_purge_data() to allow the field storage module to delete field data information.
\Drupal\Core\Entity\EntityInterface $entity: The pseudo-entity whose field data to delete.
$field: The (possibly deleted) field whose data is being purged.
$instance: The deleted field instance whose data is being purged.
Note: this list is generated by pattern matching, so it may include some functions that are not actually implementations of this hook.
function hook_field_storage_purge(\Drupal\Core\Entity\EntityInterface $entity, $field, $instance) {
$table_name = _field_sql_storage_tablename($field);
$revision_name = _field_sql_storage_revision_tablename($field);
db_delete($table_name)
->condition('entity_type', $entity
->entityType())
->condition('entity_id', $entity
->id())
->execute();
db_delete($revision_name)
->condition('entity_type', $entity
->entityType())
->condition('entity_id', $entity
->id())
->execute();
}