bibcite-8.x-1.x-dev/modules/bibcite_entity/src/ReferenceStorageSchema.php

<?php

namespace Drupal\bibcite_entity;

use Drupal\Core\Entity\ContentEntityTypeInterface;
use Drupal\Core\Entity\Sql\SqlContentEntityStorageSchema;
use Drupal\Core\Field\FieldStorageDefinitionInterface;

/**
 * Defines the reference schema handler.
 */
class ReferenceStorageSchema extends SqlContentEntityStorageSchema {

  /**
   * {@inheritdoc}
   */
  protected function getSharedTableFieldSchema(FieldStorageDefinitionInterface $storage_definition, $table_name, array $column_mapping) {
    $schema = parent::getSharedTableFieldSchema($storage_definition, $table_name, $column_mapping);
    $field_name = $storage_definition->getName();

    if ($table_name == 'bibcite_reference_revision') {
      switch ($field_name) {
        case 'revision_user':
          $this->addSharedTableFieldForeignKey($storage_definition, $schema, 'users', 'uid');
          break;
      }
    }

    if ($table_name == 'bibcite_reference_field_data') {
      switch ($field_name) {
        case 'changed':
        case 'created':
          // @todo Revisit index definitions:
          //   https://www.drupal.org/node/2015277.
          $this->addSharedTableFieldIndex($storage_definition, $schema, TRUE);
          break;
      }
    }

    return $schema;
  }

  /**
   * {@inheritdoc}
   */
  protected function getDedicatedTableSchema(FieldStorageDefinitionInterface $storage_definition, ContentEntityTypeInterface $entity_type = NULL) {
    $schema = parent::getDedicatedTableSchema($storage_definition, $entity_type);
    if ($storage_definition->getName() === 'bibcite_citekey') {
      /** @var \Drupal\Core\Entity\Sql\DefaultTableMapping $table_mapping */
      $table_mapping = $this->storage->getTableMapping();
      $dedicated_table_name = $table_mapping->getDedicatedDataTableName($storage_definition);
      $revision_dedicated_table_name = $table_mapping->getDedicatedRevisionTableName($storage_definition);
      $column_name = $table_mapping->getFieldColumnName($storage_definition, 'value');
      $schema[$dedicated_table_name]['indexes']['value'] = [$column_name];
      $schema[$revision_dedicated_table_name]['indexes']['value'] = [$column_name];
    }
    return $schema;
  }

}