Method column_descriptions

lib/sqlalchemy/sql/selectable.py:5712–5753

Return a :term:`plugin-enabled` 'column descriptions' structure referring to the columns which are SELECTed by this statement. This attribute is generally useful when using the ORM, as an extended structure which includes information about mapped entities is returned

(self)

    @property
    def column_descriptions(self) -> Any:
        """Return a :term:`plugin-enabled` 'column descriptions' structure
        referring to the columns which are SELECTed by this statement.

        This attribute is generally useful when using the ORM, as an
        extended structure which includes information about mapped
        entities is returned.  The section :ref:`queryguide_inspection`
        contains more background.

        For a Core-only statement, the structure returned by this accessor
        is derived from the same objects that are returned by the
        :attr:`.Select.selected_columns` accessor, formatted as a list of
        dictionaries which contain the keys ``name``, ``type`` and ``expr``,
        which indicate the column expressions to be selected::

            >>> stmt = select(user_table)
            >>> stmt.column_descriptions
            [
                {
                    'name': 'id',
                    'type': Integer(),
                    'expr': Column('id', Integer(), ...)},
                {
                    'name': 'name',
                    'type': String(length=30),
                    'expr': Column('name', String(length=30), ...)}
            ]

        .. versionchanged:: 1.4.33 The :attr:`.Select.column_descriptions`
           attribute returns a structure for a Core-only set of entities,
           not just ORM-only entities.

        .. seealso::

            :attr:`.UpdateBase.entity_description` - entity information for
            an :func:`.insert`, :func:`.update`, or :func:`.delete`

            :ref:`queryguide_inspection` - ORM background

        """
        meth = SelectState.get_plugin_class(self).get_column_descriptions
        return meth(self)

    def from_statement(
        self, statement: roles.ReturnsRowsRole