Added note on ODM id notation being different

toby-griffiths · xabbuh · commit 21733afb97d7 · 2016-11-05T11:38:05.000+01:00
As the ODM YML notation for the `id` field is different, I've added a note, as I spent ages wondering why it wasn't working for me.
diff --git a/doctrine.rst b/doctrine.rst
@@ -337,6 +337,11 @@ directly inside the ``Product`` class via DocBlock annotations:
     not possible to mix YAML metadata definitions with annotated PHP entity
     class definitions.
 
+.. note::
+
+    If using the Doctrine ODM the mapping of the `id` field is slightly different.  You should define the field as normal, under the `fields` key, and add `id: true` to the definition.  See the `Doctrine MongoDB YAML Driver documentation <http://docs.doctrine-project.org/projects/doctrine-mongodb-odm/en/latest/reference/yml-mapping.html>`_ for more info.
+    Using the above format will result in the error "No identifier/primary key specified for Document '<document class>'. Every Document must have an identifier/primary key.".
+
 .. tip::
 
     The table name is optional and if omitted, will be determined automatically
