<?PHP

class PDOwrap extends PDO
{

    public function fetchAll($SQL, $input_parameters=NULL)
    {
        if (false === ($stmt = $this->prepare($SQL))) return NULL;
        if (!$stmt->execute($input_parameters)) return NULL;
        return $stmt->fetchAll(PDO::FETCH_ASSOC);
    }
    
    public function fetchRow($SQL, $input_parameters=NULL)
    {
        if (false === ($stmt = $this->prepare($SQL))) return NULL;
        if (!$stmt->execute($input_parameters)) return NULL;
        return $stmt->fetch(PDO::FETCH_ASSOC);
    }
    
    public function fetchScalar($SQL, $input_parameters=NULL, $column_number=NULL)
    {
        if (false === ($stmt = $this->prepare($SQL))) return NULL;
        if (!$stmt->execute($input_parameters)) return NULL;
        $result = [];
        while (false !== ($colmn = $stmt->fetchColumn($column_number))) $result[] = $colmn;
        return $result;
    }
    
    public function exec2($SQL, $input_parameters)
    {
        if (false === ($stmt = $this->prepare($SQL))) return NULL;
        if (!$stmt->execute($input_parameters)) return NULL;
        return TRUE;
    }

}