> ## 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.ExternalColumn Column of an external table. | | | | ------------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------------------------------------------------------------ | | [`data_type`](./atoti.directquery.ExternalColumn.data_type#atoti.ExternalColumn.data_type) | The type of the elements in the column. | | [`isin`](./atoti.directquery.ExternalColumn.isin#atoti.ExternalColumn.isin) | Return a condition evaluating to `True` for elements of this column included in the given *elements*, and evaluating to `False` elsewhere. | | [`isnull`](./atoti.directquery.ExternalColumn.isnull#atoti.ExternalColumn.isnull) | Return a condition evaluating to `True` where this container evaluates to `None`, and evaluating to `False` elsewhere. | | [`name`](./atoti.directquery.ExternalColumn.name#atoti.ExternalColumn.name) | The name of the column. |