Function write

python/pathway/io/mongodb/__init__.py:321–594

Writes ``table`` to a MongoDB table. The output table supports two formats, controlled by the ``output_table_type`` parameter. The ``stream_of_changes`` format provides a complete history of all modifications applied to the table. Each entry contains the full data row along with tw

(
    table: Table,
    *,
    connection_string: str,
    database: str,
    collection: str,
    output_table_type: Literal["stream_of_changes", "snapshot"] = "stream_of_changes",
    max_batch_size: int | None = None,
    name: str | None = None,
    sort_by: Iterable[ColumnReference] | None = None,
)

@check_arg_types
@trace_user_frame
def write(
    table: Table,
    *,
    connection_string: str,
    database: str,
    collection: str,
    output_table_type: Literal["stream_of_changes", "snapshot"] = "stream_of_changes",
    max_batch_size: int | None = None,
    name: str | None = None,
    sort_by: Iterable[ColumnReference] | None = None,
) -> None:
    """Writes ``table`` to a MongoDB table.

    The output table supports two formats, controlled by the ``output_table_type``
    parameter.

    The ``stream_of_changes`` format provides a complete history of all modifications
    applied to the table. Each entry contains the full data row along with two
    additional fields: ``time`` and ``diff``. The ``time`` field identifies the
    transactional minibatch in which the change occurred, while ``diff`` describes
    the nature of the change: ``diff = 1`` indicates that the row was inserted into
    the Pathway Live Data Framework table, and ``diff = -1`` indicates that the row was removed. Row
    updates are represented as two events within the same transactional minibatch:
    first the old version of the row with ``diff = -1``, followed by the new version
    with ``diff = 1``. This format is used by default. Because ``time`` and ``diff``
    are reserved field names in this format, the input table must not contain columns
    with these names; otherwise a ``ValueError`` is raised at construction time.

    The ``snapshot`` format maintains the current state of the Pathway Live Data Framework table in the
    output. The table's primary key is stored in the ``_id`` field. When a change
    occurs, no additional metadata fields are added; instead, the engine locates the
    corresponding row by ``_id`` and applies the update directly. As a result, the
    output table always reflects the latest state of the Pathway Live Data Framework table.

    **Reserved column name**: in both formats, the input table must not contain a
    column named ``_id`` — MongoDB uses ``_id`` as the primary key for every
    document. A ``ValueError`` is raised at construction time if this column is
    present.

    If the specified database or table doesn't exist, it will be created during the
    first write.

    **Note:** Since MongoDB
    `stores DateTime in milliseconds <https://www.mongodb.com/docs/manual/reference/bson-types/#date>`_,
    the `Duration </developers/api-docs/pathway/#pathway.Duration>`_ type is also
    serialized as an integer number of milliseconds for consistency.

    Args:
        table: The table to output.
        connection_string: The connection string for the MongoDB database. See the \
`MongoDB documentation <https://www.mongodb.com/docs/manual/reference/connection-string/>`_ \
for the details.
        database: The name of the database to update.
        collection: The name of the collection to write to.
        output_table_type: The type of the output table, defining whether a current snapshot
            or a history of modifications must be maintained.
        max_batch_size: The maximum number of entries to insert in one batch.
        name: A unique name for the connector. If provided, this name will be used in