Function from_dml_column

lib/sqlalchemy/sql/_elements_constructors.py:492–524

r"""A placeholder that may be used in compiled INSERT or UPDATE expressions to refer to the SQL expression or value being applied to another column. Given a table such as:: t = Table( "t", MetaData(), Column("x", Integer), Column("y",

(column: _OnlyColumnArgument[_T])

def from_dml_column(column: _OnlyColumnArgument[_T]) -> DMLTargetCopy[_T]:
    r"""A placeholder that may be used in compiled INSERT or UPDATE expressions
    to refer to the SQL expression or value being applied to another column.

    Given a table such as::

        t = Table(
            "t",
            MetaData(),
            Column("x", Integer),
            Column("y", Integer),
        )

    The :func:`_sql.from_dml_column` construct allows automatic copying
    of an expression assigned to a different column to be reused::

        >>> stmt = t.insert().values(x=func.foobar(3), y=from_dml_column(t.c.x) + 5)
        >>> print(stmt)
        INSERT INTO t (x, y) VALUES (foobar(:foobar_1), (foobar(:foobar_1) + :param_1))

    The :func:`_sql.from_dml_column` construct is intended to be useful primarily
    with event-based hooks such as those used by ORM hybrids.

    .. seealso::

        :ref:`hybrid_bulk_update`

    .. versionadded:: 2.1


    """  # noqa: E501

    return DMLTargetCopy(column)


def bindparam(