code: protected function getTableNameAndAlias()
      {
          if (empty($this->from)) {
              $tableName = $this->getPrimaryTableName();
          } else {
              $tableName = '';
              // if the first entry in "from" is an alias-tablename-pair return it directly
              foreach ($this->from as $alias => $tableName) {
                  if (is_string($alias)) {
                      return [$tableName, $alias];
                  }
                  break;
              }
          }
  
          if (preg_match('/^(.*?)\s+({{\w+}}|\w+)$/', $tableName, $matches)) {
              $alias = $matches[2];
          } else {
              $alias = $tableName;
          }
  
          return [$tableName, $alias];
      }
docs: Returns the table name and the table alias for [[modelClass]].
  @return array the table name and the table alias.
  @since 2.0.16