致命错误：在非对象上调用成员函数persist（）

Question

Fatal error: Call to a member function persist() on a non-object

我正在使用作曲家，mongodb doctrine，php

namespace Documents;

public $document_id;
public $id;
public $model;
public function __construct($model){
     $this->model = $model;
     $car = new Car('Ford');
     dm->persist($car);
     dm->flush();
     var_dump($car->__toString());

Answer 1

您的示例中没有定义$dm变量。请尝试：

$dm = $this->get('doctrine.odm.mongodb.document_manager');
$dm->persist($car);
$dm->flush();

在文档中有详细描述 - http://symfony.com/doc/2.0/bundles/DoctrineMongoDBBundle/index.html