FluentStructure::getPrimaryKey PHP Method

    public function getPrimaryKey($table)
    {
        return $this->key($this->primaryKey, $table);
    }

 /**
  * Create SELECT query from $table
  *
  * @param string  $table      - db table name
  * @param integer $primaryKey - return one row by primary key
  *
  * @return \SelectQuery
  */
 public function from($table, $primaryKey = null)
 {
     $query = new SelectQuery($this, $table);
     if ($primaryKey !== null) {
         $tableTable = $query->getFromTable();
         $tableAlias = $query->getFromAlias();
         $primaryKeyName = $this->structure->getPrimaryKey($tableTable);
         $query = $query->where("{$tableAlias}.{$primaryKeyName}", $primaryKey);
     }
     return $query;
 }