# DuckDBLoader

> **Class** in `langchain_community`

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

Load from `DuckDB`.

Each document represents one row of the result. The `page_content_columns`
are written into the `page_content` of the document. The `metadata_columns`
are written into the `metadata` of the document. By default, all columns
are written into the `page_content` and none into the `metadata`.

## Signature

```python
DuckDBLoader(
    self,
    query: str,
    database: str = ':memory:',
    read_only: bool = False,
    config: Optional[Dict[str, str]] = None,
    page_content_columns: Optional[List[str]] = None,
    metadata_columns: Optional[List[str]] = None,
)
```

## Parameters

| Name | Type | Required | Description |
|------|------|----------|-------------|
| `query` | `str` | Yes | The query to execute. |
| `database` | `str` | No | The database to connect to. Defaults to ":memory:". (default: `':memory:'`) |
| `read_only` | `bool` | No | Whether to open the database in read-only mode. Defaults to False. (default: `False`) |
| `config` | `Optional[Dict[str, str]]` | No | A dictionary of configuration options to pass to the database. Optional. (default: `None`) |
| `page_content_columns` | `Optional[List[str]]` | No | The columns to write into the `page_content` of the document. Optional. (default: `None`) |
| `metadata_columns` | `Optional[List[str]]` | No | The columns to write into the `metadata` of the document. Optional. (default: `None`) |

## Extends

- `BaseLoader`

## Constructors

```python
__init__(
    self,
    query: str,
    database: str = ':memory:',
    read_only: bool = False,
    config: Optional[Dict[str, str]] = None,
    page_content_columns: Optional[List[str]] = None,
    metadata_columns: Optional[List[str]] = None,
)
```

| Name | Type |
|------|------|
| `query` | `str` |
| `database` | `str` |
| `read_only` | `bool` |
| `config` | `Optional[Dict[str, str]]` |
| `page_content_columns` | `Optional[List[str]]` |
| `metadata_columns` | `Optional[List[str]]` |


## Properties

- `query`
- `database`
- `read_only`
- `config`
- `page_content_columns`
- `metadata_columns`

## Methods

- [`load()`](https://reference.langchain.com/python/langchain-community/document_loaders/duckdb_loader/DuckDBLoader/load)

---

[View source on GitHub](https://github.com/langchain-ai/langchain-community/blob/4b280287bd55b99b44db2dd849f02d66c89534d5/libs/community/langchain_community/document_loaders/duckdb_loader.py#L8)