尝试从命名空间加载类您是否忘记了另一个命名空间的“使用”语句？

Question

我在我的代码中使用了 Cassandra 类，并且此错误始终显示“尝试从命名空间加载类，您是否忘记了另一个命名空间的“使用”语句？”这是我的代码

默认控制器

<?php

namespace Acme\SampleBundle\Controller;

use Symfony\Bundle\FrameworkBundle\Controller\Controller;
use Cassandra;

class DefaultController extends Controller
{
public function indexAction()
{
    $con = new Cassandra\Timestamp();

    echo $con;
}
}

时间戳.php

<?php

/**
* Copyright 2015-2016 DataStax, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/

namespace Cassandra;

/**
* A PHP representation of the CQL `timestamp` datatype
*/
final class Timestamp implements Value
{
/**
 * Creates a new timestamp from either unix timestamp and microseconds or
 * from the current time by default.
 *
 * @param int $time Unix timestamp
 * @param int $usec Microseconds
 */
public function __construct($time = null, $usec = null) {}

/**
 * The type of this timestamp.
 *
 * @return Type
 */
public function type() {}

/**
 * Unix timestamp.
 *
 * @return int seconds
 * @see time
 */
public function time() {}

/**
 * Microtime from this timestamp
 *
 * @param bool $get_as_float Whether to get this value as float
 *
 * @return float|string Float or string representation
 * @see microtime
 */
public function microtime($get_as_float = false) {}

/**
 * Converts current timestamp to PHP DateTime.
 *
 * @return \DateTime PHP representation
 */
public function toDateTime() {}

/**
 * Returns a string representation of this timestamp.
 *
 * @return string timestamp
 */
public function __toString() {}
}

我不知道我的代码有什么问题，我是使用 Cassandra 和 symfony 的新手

Answer 1

你是在配置文件中定义keyspace吗？

你可以找到一个例子here