symfony 2 : Namespace “Acme” does not contain any mapped entities

Question

I am following the book and on the page http://symfony.com/doc/current/book/doctrine.html

While following the book I am trying to work on relationship of product and cat

Answer 1

In book http://symfony.com/doc/current/book/doctrine.html entity Porduct has been manually created. You wrote code to Product.php. All information about entity fields contains in annotations.
But entity Category has been created with

php app/console doctrine:generate:entity --entity="AcmeStoreBundle:Category" --fields="name:string(255)"

Automatically generated entity Caterory.php doesn't contains annotations. Symfony stored information in "Acme\StoreBundle\Resources\config\doctrine\Category.orm.yml". That's why php app/console doctrine:mapping:info says that you have only 1 mapped entity - Category.

Solving
You may generate Product entity with doctrine:generate:entity
or
Manually add information about Product entity to "Acme\StoreBundle\Resources\config\doctrine\Category.orm.yml"
or
Delete "Acme\StoreBundle\Resources\config\doctrine\Category.orm.yml" and describe Category entity with annotations in Category.php

Answer 2

Check that the PHP opening and (optional) closing tags

<?php  

and

?>

are correct in your file.

They are not included when you copy paste from the tutorial at http://symfony.com/doc/current/book/doctrine.html

I was stuck at the same problem. After looking at this post I started wondering why the syntax highlighting was broken and discovered that the opening and closing tags were missing. The error disappeared when the tags were included.

Answer 3

The solution:

Update symfony files:

composer update

then create entities

php bin/console doctrine:generate:entities BackendBundle

Answer 4

This error will also come up if your projects (only?) Entity is namespaced incorrectly. If you run the command

$ php app/console doctrine:generate:entities MyBundle

and it produces the error

[RuntimeException]
Bundle "MyBundle" does not contain any mapped entities.

Check the more specific command....

$ php app/console doctrine:generate:entities MyBundle:MyEntity

And see if you get the error:

[RuntimeException]
The autoloader expected class "MyBundle\Entity\MyEntity" to be defined in file "/path/to/MyBundle/Entity/MyEntity.php". The file was found but the class was not in it, the class name or namespace probably has a typo.

If so, well then, the error speaks for itself (hopefully) and the namespace/class name needs to be corrected. Hopefully that is helpful to someone.

Answer 5

With

doctrine:generate:entity

you'll create new entity.

And when you add some attributes by hand with

doctrine:generate:entities AcmeDemoBundle:User

you'll create all accessor (getter and setter) of the entity User of AcmeDemoBundle

Answer 6

I personally had the error because I was missing the folder/directory "Entity".