Mastering MongoDB 4.x - Second Edition

Querying documents

Querying is done using QuerySet, as described before the update and delete operations.

Some convenience methods available include the following:

• all()
• count()
• first()
• exclude(*fields) to exclude some fields from the result
• only(*fields) to include only some fields in the result (this can be chained for a union of fields)
• limit(limit)
• order_by(ordering)
• reverse() if we want to reverse the order_by() order
• skip(number)
• values() to return Python dict instances instead of model instances

By using raw(), we can use the same queries that we described in the previous PyMongo section for querying and still exploit the flexibility and convenience methods provided by the ODM layer.