我正在扩展具有两种抽象方法的抽象类。 当我尝试实例化的子类,我得到以下错误,未捕获错误:无法调用抽象方法(PHP致命错误)
PHP Fatal error: Uncaught Error: Cannot call abstract method GetAnswer::GetAnswer()
当我注释掉两个父母和孩子的事情GetAnswer()
做工精细。
PHP版本:7.0.2在XAMPP中,运行在Wondows 8.1上。
父类文件app-的getAnswer-base.php如下
<?php
abstract class GetAnswer{
abstract public function GetAnswer($Username, $QuestionnaireID, $QuestionID);
abstract public function GetAnswers($Username, $QuestionnaireID);
}
儿童类文件app-getAnswer-db-direct.php
如下
<?php
require_once 'config-db-login.php';
require_once 'app-getAnswer-base.php';
class GetAnswer_SQLSelect extends GetAnswer {
public function GetAnswer($Username, $QuestionnaireID, $QuestionID){
return null;
}
public function GetAnswers($Username, $QuestionnaireID){
$connection = new mysqli(dbLogin::$db_hostname, dbLogin::$db_username, dbLogin::$db_password, dbLogin::$db_database);
if ($connection->connect_error) die($connection->connect_error);
$query = "SELECT `QuestionID`, `Answer` FROM `answerstore`.`answers` AS a JOIN `answerstore`.`participants` AS b ON a.`ParticipantID` = b.`ParticipantID` WHERE a.`QuestionnaireID` = '$QuestionnaireID' AND b.`Username`='$Username'";
$result = $connection->query($query);
$connection->close();
return $result;
}
}
显示引发错误的调用的代码。 – Tschallacka
@MichaelDibbets,是'$ getAnswers = new GetAnswer_SQLSelect();' – Gamaka