Function extract

lib/sqlalchemy/sql/_elements_constructors.py:1243–1285

Return a :class:`.Extract` construct. This is typically available as :func:`.extract` as well as ``func.extract`` from the :data:`.func` namespace. :param field: The field to extract. .. warning:: This field is used as a literal SQL string. **DO NOT PASS UNTRUSTED IN

(field: str, expr: _ColumnExpressionArgument[Any])

def extract(field: str, expr: _ColumnExpressionArgument[Any]) -> Extract:
    """Return a :class:`.Extract` construct.

    This is typically available as :func:`.extract`
    as well as ``func.extract`` from the
    :data:`.func` namespace.

    :param field: The field to extract.

     .. warning:: This field is used as a literal SQL string.
         **DO NOT PASS UNTRUSTED INPUT TO THIS STRING**.

    :param expr: A column or Python scalar expression serving as the
      right side of the ``EXTRACT`` expression.

    E.g.::

        from sqlalchemy import extract
        from sqlalchemy import table, column

        logged_table = table(
            "user",
            column("id"),
            column("date_created"),
        )

        stmt = select(logged_table.c.id).where(
            extract("YEAR", logged_table.c.date_created) == 2021
        )

    In the above example, the statement is used to select ids from the
    database where the ``YEAR`` component matches a specific value.

    Similarly, one can also select an extracted component::

        stmt = select(extract("YEAR", logged_table.c.date_created)).where(
            logged_table.c.id == 1
        )

    The implementation of ``EXTRACT`` may vary across database backends.
    Users are reminded to consult their database documentation.
    """
    return Extract(field, expr)


def false() -> False_: