在PHP中正确关闭数据库连接

Question

我在PHP数据库连接方面遇到了一些疑问。既然我不能在我的方法上放一个很大的try/catch/finally块(Java风格)，那么当大小/逻辑趋于增长时，正确关闭所有连接和准备好的语句的最佳方法是什么？考虑下一种方法，一切都是正确的吗？

public function createRegister($register) {
        $this->openConnection();

        $query = "INSERT INTO register (username, password, email, confirmationToken) VALUES (?, ?, ?, ?)";
        $result = $this->mysqli->query($query);

        if ($statement = $this->mysqli->prepare($query)) {  
            $statement->bind_param("ssss", $register->username, $register->passwordHash, $register->email, $register->confirmationToken);

            if (!$statement->execute()) {
                $this->closeConnection();
                throw new DAOException("Failed to execute statement: " . $statement->error);
            }

            $statement->close();

        } else {
            $this->closeConnection();
            throw new DAOException("Failed to prepare statement: " . $this->mysqli->error);
        }

        $this->closeConnection();
    }

Answer 1

您仍然可以在PHP中使用try/catch：

public function createRegister($register) {

    $this->openConnection();

    $query = "INSERT INTO register (username, password, email, confirmationToken) VALUES (?, ?, ?, ?)";

    try {

        // This line is not needed
        // $result = $this->mysqli->query($query);

        if ($statement = $this->mysqli->prepare($query)) {

            $statement->bind_param("ssss", $register->username, $register->passwordHash, $register->email, $register->confirmationToken);

            if (!$statement->execute()) {                   
                throw new DAOException("Failed to execute statement: " . $statement->error);
            }

            $statement->close();

        } else {
            throw new DAOException("Failed to prepare statement: " . $this->mysqli->error);
        }
    } catch (Exception $e) {

        if ((isset($statement)) && (is_callable(array($statement, 'close')))) {
            $statment->close();
        }

        $this->closeConnection();

        throw $e;
    }

    $this->closeConnection();
}

这对于为一个特定任务建立连接很有效，但是如果您希望为也需要访问相同模式的多个任务共享相同的连接，该怎么办呢？您可能希望考虑一种更高级的解决方案，使用单例/工厂模式创建和访问数据库连接。我发布了这样一个example，作为对另一个问题的解决方案。它有点高级，但一旦你掌握了它，它的性能就会更好。