# MongoDBLoader

> **Class** in `langchain_mongodb`

📖 [View in docs](https://reference.langchain.com/python/langchain-mongodb/loaders/MongoDBLoader)

Document Loaders are classes to load Documents.

Document Loaders are usually used to load a lot of Documents in a single run.

## Signature

```python
MongoDBLoader(
    self,
    collection: Collection,
    *,
    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 |
|------|------|----------|-------------|
| `collection` | `Collection` | Yes | The pymongo 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,
    collection: Collection,
    *,
    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 |
|------|------|
| `collection` | `Collection` |
| `filter_criteria` | `Optional[Dict]` |
| `field_names` | `Optional[Sequence[str]]` |
| `metadata_names` | `Optional[Sequence[str]]` |
| `include_db_collection_in_metadata` | `bool` |


## Properties

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

## Methods

- [`from_connection_string()`](https://reference.langchain.com/python/langchain-mongodb/loaders/MongoDBLoader/from_connection_string)
- [`close()`](https://reference.langchain.com/python/langchain-mongodb/loaders/MongoDBLoader/close)
- [`load()`](https://reference.langchain.com/python/langchain-mongodb/loaders/MongoDBLoader/load)
- [`aload()`](https://reference.langchain.com/python/langchain-mongodb/loaders/MongoDBLoader/aload)

---

[View source on GitHub](https://github.com/langchain-ai/langchain-mongodb/blob/ad9050c28e092b335dcb846f77c0ec2245553f79/libs/langchain-mongodb/langchain_mongodb/loaders.py#L18)