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Document serialization uses field order to ensure a strict order is set (#296)

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This commit is contained in:
Ross Lawley
2013-04-26 11:38:45 +00:00
parent 2447349383
commit 36993097b4
8 changed files with 94 additions and 23 deletions
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4
docs/guide/defining-documents.rst
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@@ -24,6 +24,9 @@ objects** as class attributes to the document class::
title = StringField(max_length=200, required=True)
date_modified = DateTimeField(default=datetime.datetime.now)
As BSON (the binary format for storing data in mongodb) is order dependent,
documents are serialized based on their field order.
Dynamic document schemas
========================
One of the benefits of MongoDb is dynamic schemas for a collection, whilst data
@@ -51,6 +54,7 @@ be saved ::
There is one caveat on Dynamic Documents: fields cannot start with `_`
Dynamic fields are stored in alphabetical order *after* any declared fields.
Fields
======

14
docs/guide/document-instances.rst
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@@ -30,11 +30,14 @@ already exist, then any changes will be updated atomically. For example::
.. note::
Changes to documents are tracked and on the whole perform `set` operations.
Changes to documents are tracked and on the whole perform ``set`` operations.
* ``list_field.pop(0)`` - *sets* the resulting list
* ``list_field.push(0)`` - *sets* the resulting list
* ``del(list_field)`` - *unsets* whole list
With lists its preferable to use ``Doc.update(push__list_field=0)`` as
this stops the whole list being updated - stopping any race conditions.
.. seealso::
:ref:`guide-atomic-updates`
@@ -70,9 +73,10 @@ Cascading Saves
---------------
If your document contains :class:`~mongoengine.fields.ReferenceField` or
:class:`~mongoengine.fields.GenericReferenceField` objects, then by default the
:meth:`~mongoengine.Document.save` method will automatically save any changes to
those objects as well. If this is not desired passing :attr:`cascade` as False
to the save method turns this feature off.
:meth:`~mongoengine.Document.save` method will not save any changes to
those objects. If you want all references to also be saved also, noting each
save is a separate query, then passing :attr:`cascade` as True
to the save method will cascade any saves.
Deleting documents
------------------