Class CompoundSelect

lib/sqlalchemy/sql/selectable.py:4511–4722

Forms the basis of ``UNION``, ``UNION ALL``, and other SELECT-based set operations. .. seealso:: :func:`_expression.union` :func:`_expression.union_all` :func:`_expression.intersect` :func:`_expression.intersect_all` :func:`_expression.except`

class CompoundSelect(HasCompileState, GenerativeSelect, TypedReturnsRows[_TP]):
    """Forms the basis of ``UNION``, ``UNION ALL``, and other
    SELECT-based set operations.


    .. seealso::

        :func:`_expression.union`

        :func:`_expression.union_all`

        :func:`_expression.intersect`

        :func:`_expression.intersect_all`

        :func:`_expression.except`

        :func:`_expression.except_all`

    """

    __visit_name__ = "compound_select"

    _traverse_internals: _TraverseInternalsType = (
        [
            ("selects", InternalTraversal.dp_clauseelement_list),
            ("_limit_clause", InternalTraversal.dp_clauseelement),
            ("_offset_clause", InternalTraversal.dp_clauseelement),
            ("_fetch_clause", InternalTraversal.dp_clauseelement),
            ("_fetch_clause_options", InternalTraversal.dp_plain_dict),
            ("_order_by_clauses", InternalTraversal.dp_clauseelement_list),
            ("_group_by_clauses", InternalTraversal.dp_clauseelement_list),
            ("_for_update_arg", InternalTraversal.dp_clauseelement),
            ("keyword", InternalTraversal.dp_string),
        ]
        + SupportsCloneAnnotations._clone_annotations_traverse_internals
        + HasCTE._has_ctes_traverse_internals
        + DialectKWArgs._dialect_kwargs_traverse_internals
        + Executable._executable_traverse_internals
    )

    selects: List[SelectBase]

    _is_from_container = True
    _auto_correlate = False

    def __init__(
        self,
        keyword: _CompoundSelectKeyword,
        *selects: _SelectStatementForCompoundArgument[_TP],
    ):
        self.keyword = keyword
        self.selects = [
            coercions.expect(
                roles.CompoundElementRole, s, apply_propagate_attrs=self
            ).self_group(against=self)
            for s in selects
        ]