public function getOne($sql, $params = array(), $column_number = 0)
    {
        $stmt = $this->execute($sql, $params);
        return $stmt->fetchColumn($column_number);
    }
public function getOne($sql, $params = array(), $column_number = 0)
    {
        $stmt = $this->execute($sql, $params);
        return $stmt->fetchColumn($column_number);
    }
public function getOne ( $ sql , $ params = array ( ) , $ column_number = 0 ) { $ stmt = $ this -> execute ( $ sql , $ params ) ; return $ stmt -> fetchColumn ( $ column_number ) ; }
Get one column result

@param       $sql
@param array $params
@param int   $column_number

@return string
Get one column result