# MongodbLoader

> **Class** in `langchain_community`

📖 [View in docs](https://reference.langchain.com/python/langchain-community/document_loaders/mongodb/MongodbLoader)

Load MongoDB documents.

## Signature

```python
MongodbLoader(
    self,
    connection_string: str,
    db_name: str,
    collection_name: str,
    *,
    filter_criteria: Optional[Dict] = None,
    field_names: Optional[Sequence[str]] = None,
    metadata_names: Optional[Sequence[str]] = None,
    include_db_collection_in_metadata: bool = True,
)
```

## Parameters

| Name | Type | Required | Description |
|------|------|----------|-------------|
| `connection_string` | `str` | Yes | MongoDB connection URI. |
| `db_name` | `str` | Yes | Name of the database to connect to. |
| `collection_name` | `str` | Yes | Name of the collection to fetch documents from. |
| `filter_criteria` | `Optional[Dict]` | No | MongoDB filter criteria for querying (default: `None`) |
| `field_names` | `Optional[Sequence[str]]` | No | List of field names to retrieve (default: `None`) |
| `metadata_names` | `Optional[Sequence[str]]` | No | Additional metadata fields to (default: `None`) |
| `include_db_collection_in_metadata` | `bool` | No | Flag to include database and (default: `True`) |

## Extends

- `BaseLoader`

## Constructors

```python
__init__(
    self,
    connection_string: str,
    db_name: str,
    collection_name: str,
    *,
    filter_criteria: Optional[Dict] = None,
    field_names: Optional[Sequence[str]] = None,
    metadata_names: Optional[Sequence[str]] = None,
    include_db_collection_in_metadata: bool = True,
) -> None
```

| Name | Type |
|------|------|
| `connection_string` | `str` |
| `db_name` | `str` |
| `collection_name` | `str` |
| `filter_criteria` | `Optional[Dict]` |
| `field_names` | `Optional[Sequence[str]]` |
| `metadata_names` | `Optional[Sequence[str]]` |
| `include_db_collection_in_metadata` | `bool` |


## Properties

- `client`
- `db_name`
- `collection_name`
- `field_names`
- `filter_criteria`
- `metadata_names`
- `include_db_collection_in_metadata`
- `db`
- `collection`

## Methods

- [`load()`](https://reference.langchain.com/python/langchain-community/document_loaders/mongodb/MongodbLoader/load)
- [`lazy_load()`](https://reference.langchain.com/python/langchain-community/document_loaders/mongodb/MongodbLoader/lazy_load)
- [`alazy_load()`](https://reference.langchain.com/python/langchain-community/document_loaders/mongodb/MongodbLoader/alazy_load)
- [`aload()`](https://reference.langchain.com/python/langchain-community/document_loaders/mongodb/MongodbLoader/aload)

---

[View source on GitHub](https://github.com/langchain-ai/langchain-community/blob/4b280287bd55b99b44db2dd849f02d66c89534d5/libs/community/langchain_community/document_loaders/mongodb.py#L12)