MongoEngine / MongoEngine/mongoengine

Unable to insert null into collection

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Dominant language
Python
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Description

I am currently using the DynamicDocument object and have only some pre-defined fields (i.e. user id). The remaining fields are all dynamic. Some of these dynamic fields will be specified with a valid key and a "None" for value. When I try to save the document to MongoDB, the keys with a "None" value are not inserted into the collection. Looking at the BaseDocument to_mongo function, this behavior seems intended.

What is the reasoning behind not inserting null values? I verified that removing the "if value is not None" statement, allows me to insert null into the database.

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Research direction

Start with mongoengine/base/document.py and the BaseDocument.to_mongo function referenced in the issue; inspect how DynamicDocument fields with None values are handled and look for related tests. Done means the expected persistence behavior for dynamic keys whose values are None is defined and verified against MongoDB serialization.

Written by the indexing model from the issue text.

Assessment

Tech stack
mongodb, python
Domain
databases
Issue type
Feature
Difficulty
2/5
Estimated time
1-3 hours
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
38/100

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