SqlContentEntityStorage::loadFromSharedTables

protected SqlContentEntityStorage::loadFromSharedTables(array &$values, array &$translations)

protected function loadFromSharedTables(array &$values, array &$translations) {
  if ($this->dataTable) {
    // If a revision table is available, we need all the properties of the
    // latest revision. Otherwise we fall back to the data table.
    $table = $this->revisionDataTable ? : $this->dataTable;
    $alias = $this->revisionDataTable ? 'revision' : 'data';
    $query = $this->database->select($table, $alias, array('fetch' => \PDO::FETCH_ASSOC))
      ->fields($alias)
      ->condition($alias . '.' . $this->idKey, array_keys($values), 'IN')
      ->orderBy($alias . '.' . $this->idKey);

    $table_mapping = $this->getTableMapping();
    if ($this->revisionDataTable) {
      // Find revisioned fields that are not entity keys. Exclude the langcode
      // key as the base table holds only the default language.
      $base_fields = array_diff($table_mapping->getFieldNames($this->baseTable), array($this->langcodeKey));
      $revisioned_fields = array_diff($table_mapping->getFieldNames($this->revisionDataTable), $base_fields);

      // Find fields that are not revisioned or entity keys. Data fields have
      // the same value regardless of entity revision.
      $data_fields = array_diff($table_mapping->getFieldNames($this->dataTable), $revisioned_fields, $base_fields);
      // If there are no data fields then only revisioned fields are needed
      // else both data fields and revisioned fields are needed to map the
      // entity values.
      $all_fields = $revisioned_fields;
      if ($data_fields) {
        $all_fields = array_merge($revisioned_fields, $data_fields);
        $query->leftJoin($this->dataTable, 'data', "(revision.$this->idKey = data.$this->idKey and revision.$this->langcodeKey = data.$this->langcodeKey)");
        $column_names = [];
        // Some fields can have more then one columns in the data table so
        // column names are needed.
        foreach ($data_fields as $data_field) {
          // \Drupal\Core\Entity\Sql\TableMappingInterface:: getColumNames()
          // returns an array keyed by property names so remove the keys
          // before array_merge() to avoid losing data with fields having the
          // same columns i.e. value.
          $column_names = array_merge($column_names, array_values($table_mapping->getColumnNames($data_field)));
        }
        $query->fields('data', $column_names);
      }

      // Get the revision IDs.
      $revision_ids = array();
      foreach ($values as $entity_values) {
        $revision_ids[] = $entity_values[$this->revisionKey][LanguageInterface::LANGCODE_DEFAULT];
      }
      $query->condition('revision.' . $this->revisionKey, $revision_ids, 'IN');
    }
    else {
      $all_fields = $table_mapping->getFieldNames($this->dataTable);
    }

    $result = $query->execute();
    foreach ($result as $row) {
      $id = $row[$this->idKey];

      // Field values in default language are stored with
      // LanguageInterface::LANGCODE_DEFAULT as key.
      $langcode = empty($row[$this->defaultLangcodeKey]) ? $row[$this->langcodeKey] : LanguageInterface::LANGCODE_DEFAULT;

      $translations[$id][$langcode] = TRUE;

      foreach ($all_fields as $field_name) {
        $columns = $table_mapping->getColumnNames($field_name);
        // Do not key single-column fields by property name.
        if (count($columns) == 1) {
          $values[$id][$field_name][$langcode] = $row[reset($columns)];
        }
        else {
          foreach ($columns as $property_name => $column_name) {
            $values[$id][$field_name][$langcode][$property_name] = $row[$column_name];
          }
        }
      }
    }
  }
}