> ## Documentation Index
> Fetch the complete documentation index at: https://docs.activeviam.com/llms.txt
> Use this file to discover all available pages before exploring further.

# atoti.Session.add_external_table()

#### Session.add\_external\_table(external\_table, /, table\_name=None, \*, columns=frozendict(\{}), config=None)

Add a table from an external database to the session.

* **Parameters:**
  * **external\_table** ([*ExternalTable*](./atoti.directquery.external_table#atoti.ExternalTable) \*\[\**ExternalDatabaseConnectionConfigT* *]*) – The external database table from which to build the session table.
    Instances of such tables are obtained through an external database connection.
  * **table\_name** ([*str*](https://docs.python.org/3/library/stdtypes.html#str) *|* *None*) – The name to give to the table in the session.
    If `None`, the name of the external table is used.
  * **columns** ([*Mapping*](https://docs.python.org/3/library/collections.abc.html#collections.abc.Mapping) *\[*[*str*](https://docs.python.org/3/library/stdtypes.html#str) *,* [*str*](https://docs.python.org/3/library/stdtypes.html#str) *]*) – Mapping from external column names to local column names.
    If empty, the local columns will share the names of the external columns.
  * **config** (*ExternalTableConfig* \*\[\**ExternalDatabaseConnectionConfigT* *]*  *|* *None*) – The config to add the external table.
    Each [DirectQuery plugin](../getting_started/plugins#directquery) has its own `TableConfig` class.
* **Return type:**
  [*Table*](./atoti.table#atoti.Table)

### Example

```pycon theme={"languages":{"custom":["/engine/python-sdk/0.9/languages/pycon.tmLanguage.json"]}}
>>> external_database = session.connect_to_external_database(
...     connection_config
... )
>>> external_table = external_database.tables["TUTORIAL", "SALES"]
>>> list(external_table)
['SALE_ID', 'DATE', 'SHOP', 'PRODUCT', 'QUANTITY', 'UNIT_PRICE']
```

Add the external table, filtering out some columns and renaming the remaining ones:

```pycon theme={"languages":{"custom":["/engine/python-sdk/0.9/languages/pycon.tmLanguage.json"]}}
>>> from atoti_directquery_snowflake import TableConfig
>>> table = session.add_external_table(
...     external_table,
...     columns={
...         "SALE_ID": "Sale ID",
...         "DATE": "Date",
...         "PRODUCT": "Product",
...         "QUANTITY": "Quantity",
...     },
...     config=TableConfig(keys={"Sale ID"}),
...     table_name="sales_renamed",
... )
>>> table.head().sort_index()
              Date Product  Quantity
Sale ID
S0007   2022-02-01   BED_2       1.0
S0008   2022-01-31   BED_2       1.0
S0009   2022-01-31   BED_2       1.0
S0010   2022-01-31   BED_2       3.0
S0019   2022-02-02   HOO_5       1.0
```