Writing to MongoDB using DBWriter

For writing data to MongoDB, use DBWriter.

Warning

Please take into account MongoDB types

Examples

from onetl.connection import MongoDB
from onetl.db import DBWriter

mongodb = MongoDB(...)

df = ...  # data is here

writer = DBWriter(
    connection=mongodb,
    target="schema.table",
    options=MongoDB.WriteOptions(
        if_exists="append",
    ),
)

writer.run(df)

Write options

Method above accepts MongoDB.WriteOptions

MongoDBWriteOptions

Bases: GenericOptions

Writing options for MongoDB connector.

.. warning::

Options ``uri``, ``database``, ``collection`` are populated from connection attributes,
and cannot be overridden by the user in ``WriteOptions`` to avoid issues.

.. versionadded:: 0.7.0

Examples:

.. note ::

You can pass any value
`supported by connector <https://www.mongodb.com/docs/spark-connector/current/batch-mode/batch-write-config/>`_,
even if it is not mentioned in this documentation. **Option names should be in** ``camelCase``!

The set of supported options depends on connector version.

.. code:: python

from onetl.connection import MongoDB

options = MongoDB.WriteOptions(
    if_exists="append",
    sampleSize=500,
    localThreshold=20,
)

if_exists = Field(default=(MongoDBCollectionExistBehavior.APPEND), alias=(avoid_alias('mode'))) class-attribute instance-attribute

Behavior of writing data into existing collection.

Possible values:

• append (default) Adds new objects into existing collection.

  .. dropdown:: Behavior in details

  * Collection does not exist
      Collection is created using options provided by user
      (``shardkey`` and others).
  
  * Collection exists
      Data is appended to a collection.
  
      .. warning::
  
          This mode does not check whether collection already contains
          objects from dataframe, so duplicated objects can be created.
  

• replace_entire_collection Collection is deleted and then created.

  .. dropdown:: Behavior in details

  * Collection does not exist
      Collection is created using options provided by user
      (``shardkey`` and others).
  
  * Collection exists
      Collection content is replaced with dataframe content.
  

• ignore Ignores the write operation if the collection already exists.

  .. dropdown:: Behavior in details

  * Collection does not exist
      Collection is created using options provided by user
  
  * Collection exists
      The write operation is ignored, and no data is written to the collection.
  

• error Raises an error if the collection already exists.

  .. dropdown:: Behavior in details

  * Collection does not exist
      Collection is created using options provided by user
  
  * Collection exists
      An error is raised, and no data is written to the collection.
  

.. versionchanged:: 0.9.0 Renamed mode → if_exists