venv

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diff --git a/venv/lib/python3.11/site-packages/sqlalchemy/engine/result.py b/venv/lib/python3.11/site-packages/sqlalchemy/engine/result.py
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+++ b/venv/lib/python3.11/site-packages/sqlalchemy/engine/result.py
@@ -0,0 +1,2382 @@
+# engine/result.py
+# Copyright (C) 2005-2024 the SQLAlchemy authors and contributors
+# <see AUTHORS file>
+#
+# This module is part of SQLAlchemy and is released under
+# the MIT License: https://www.opensource.org/licenses/mit-license.php
+
+"""Define generic result set constructs."""
+
+from __future__ import annotations
+
+from enum import Enum
+import functools
+import itertools
+import operator
+import typing
+from typing import Any
+from typing import Callable
+from typing import cast
+from typing import Dict
+from typing import Generic
+from typing import Iterable
+from typing import Iterator
+from typing import List
+from typing import Mapping
+from typing import NoReturn
+from typing import Optional
+from typing import overload
+from typing import Sequence
+from typing import Set
+from typing import Tuple
+from typing import TYPE_CHECKING
+from typing import TypeVar
+from typing import Union
+
+from .row import Row
+from .row import RowMapping
+from .. import exc
+from .. import util
+from ..sql.base import _generative
+from ..sql.base import HasMemoized
+from ..sql.base import InPlaceGenerative
+from ..util import HasMemoized_ro_memoized_attribute
+from ..util import NONE_SET
+from ..util._has_cy import HAS_CYEXTENSION
+from ..util.typing import Literal
+from ..util.typing import Self
+
+if typing.TYPE_CHECKING or not HAS_CYEXTENSION:
+    from ._py_row import tuplegetter as tuplegetter
+else:
+    from sqlalchemy.cyextension.resultproxy import tuplegetter as tuplegetter
+
+if typing.TYPE_CHECKING:
+    from ..sql.schema import Column
+    from ..sql.type_api import _ResultProcessorType
+
+_KeyType = Union[str, "Column[Any]"]
+_KeyIndexType = Union[str, "Column[Any]", int]
+
+# is overridden in cursor using _CursorKeyMapRecType
+_KeyMapRecType = Any
+
+_KeyMapType = Mapping[_KeyType, _KeyMapRecType]
+
+
+_RowData = Union[Row[Any], RowMapping, Any]
+"""A generic form of "row" that accommodates for the different kinds of
+"rows" that different result objects return, including row, row mapping, and
+scalar values"""
+
+_RawRowType = Tuple[Any, ...]
+"""represents the kind of row we get from a DBAPI cursor"""
+
+_R = TypeVar("_R", bound=_RowData)
+_T = TypeVar("_T", bound=Any)
+_TP = TypeVar("_TP", bound=Tuple[Any, ...])
+
+_InterimRowType = Union[_R, _RawRowType]
+"""a catchall "anything" kind of return type that can be applied
+across all the result types
+
+"""
+
+_InterimSupportsScalarsRowType = Union[Row[Any], Any]
+
+_ProcessorsType = Sequence[Optional["_ResultProcessorType[Any]"]]
+_TupleGetterType = Callable[[Sequence[Any]], Sequence[Any]]
+_UniqueFilterType = Callable[[Any], Any]
+_UniqueFilterStateType = Tuple[Set[Any], Optional[_UniqueFilterType]]
+
+
+class ResultMetaData:
+    """Base for metadata about result rows."""
+
+    __slots__ = ()
+
+    _tuplefilter: Optional[_TupleGetterType] = None
+    _translated_indexes: Optional[Sequence[int]] = None
+    _unique_filters: Optional[Sequence[Callable[[Any], Any]]] = None
+    _keymap: _KeyMapType
+    _keys: Sequence[str]
+    _processors: Optional[_ProcessorsType]
+    _key_to_index: Mapping[_KeyType, int]
+
+    @property
+    def keys(self) -> RMKeyView:
+        return RMKeyView(self)
+
+    def _has_key(self, key: object) -> bool:
+        raise NotImplementedError()
+
+    def _for_freeze(self) -> ResultMetaData:
+        raise NotImplementedError()
+
+    @overload
+    def _key_fallback(
+        self, key: Any, err: Optional[Exception], raiseerr: Literal[True] = ...
+    ) -> NoReturn: ...
+
+    @overload
+    def _key_fallback(
+        self,
+        key: Any,
+        err: Optional[Exception],
+        raiseerr: Literal[False] = ...,
+    ) -> None: ...
+
+    @overload
+    def _key_fallback(
+        self, key: Any, err: Optional[Exception], raiseerr: bool = ...
+    ) -> Optional[NoReturn]: ...
+
+    def _key_fallback(
+        self, key: Any, err: Optional[Exception], raiseerr: bool = True
+    ) -> Optional[NoReturn]:
+        assert raiseerr
+        raise KeyError(key) from err
+
+    def _raise_for_ambiguous_column_name(
+        self, rec: _KeyMapRecType
+    ) -> NoReturn:
+        raise NotImplementedError(
+            "ambiguous column name logic is implemented for "
+            "CursorResultMetaData"
+        )
+
+    def _index_for_key(
+        self, key: _KeyIndexType, raiseerr: bool
+    ) -> Optional[int]:
+        raise NotImplementedError()
+
+    def _indexes_for_keys(
+        self, keys: Sequence[_KeyIndexType]
+    ) -> Sequence[int]:
+        raise NotImplementedError()
+
+    def _metadata_for_keys(
+        self, keys: Sequence[_KeyIndexType]
+    ) -> Iterator[_KeyMapRecType]:
+        raise NotImplementedError()
+
+    def _reduce(self, keys: Sequence[_KeyIndexType]) -> ResultMetaData:
+        raise NotImplementedError()
+
+    def _getter(
+        self, key: Any, raiseerr: bool = True
+    ) -> Optional[Callable[[Row[Any]], Any]]:
+        index = self._index_for_key(key, raiseerr)
+
+        if index is not None:
+            return operator.itemgetter(index)
+        else:
+            return None
+
+    def _row_as_tuple_getter(
+        self, keys: Sequence[_KeyIndexType]
+    ) -> _TupleGetterType:
+        indexes = self._indexes_for_keys(keys)
+        return tuplegetter(*indexes)
+
+    def _make_key_to_index(
+        self, keymap: Mapping[_KeyType, Sequence[Any]], index: int
+    ) -> Mapping[_KeyType, int]:
+        return {
+            key: rec[index]
+            for key, rec in keymap.items()
+            if rec[index] is not None
+        }
+
+    def _key_not_found(self, key: Any, attr_error: bool) -> NoReturn:
+        if key in self._keymap:
+            # the index must be none in this case
+            self._raise_for_ambiguous_column_name(self._keymap[key])
+        else:
+            # unknown key
+            if attr_error:
+                try:
+                    self._key_fallback(key, None)
+                except KeyError as ke:
+                    raise AttributeError(ke.args[0]) from ke
+            else:
+                self._key_fallback(key, None)
+
+    @property
+    def _effective_processors(self) -> Optional[_ProcessorsType]:
+        if not self._processors or NONE_SET.issuperset(self._processors):
+            return None
+        else:
+            return self._processors
+
+
+class RMKeyView(typing.KeysView[Any]):
+    __slots__ = ("_parent", "_keys")
+
+    _parent: ResultMetaData
+    _keys: Sequence[str]
+
+    def __init__(self, parent: ResultMetaData):
+        self._parent = parent
+        self._keys = [k for k in parent._keys if k is not None]
+
+    def __len__(self) -> int:
+        return len(self._keys)
+
+    def __repr__(self) -> str:
+        return "{0.__class__.__name__}({0._keys!r})".format(self)
+
+    def __iter__(self) -> Iterator[str]:
+        return iter(self._keys)
+
+    def __contains__(self, item: Any) -> bool:
+        if isinstance(item, int):
+            return False
+
+        # note this also includes special key fallback behaviors
+        # which also don't seem to be tested in test_resultset right now
+        return self._parent._has_key(item)
+
+    def __eq__(self, other: Any) -> bool:
+        return list(other) == list(self)
+
+    def __ne__(self, other: Any) -> bool:
+        return list(other) != list(self)
+
+
+class SimpleResultMetaData(ResultMetaData):
+    """result metadata for in-memory collections."""
+
+    __slots__ = (
+        "_keys",
+        "_keymap",
+        "_processors",
+        "_tuplefilter",
+        "_translated_indexes",
+        "_unique_filters",
+        "_key_to_index",
+    )
+
+    _keys: Sequence[str]
+
+    def __init__(
+        self,
+        keys: Sequence[str],
+        extra: Optional[Sequence[Any]] = None,
+        _processors: Optional[_ProcessorsType] = None,
+        _tuplefilter: Optional[_TupleGetterType] = None,
+        _translated_indexes: Optional[Sequence[int]] = None,
+        _unique_filters: Optional[Sequence[Callable[[Any], Any]]] = None,
+    ):
+        self._keys = list(keys)
+        self._tuplefilter = _tuplefilter
+        self._translated_indexes = _translated_indexes
+        self._unique_filters = _unique_filters
+        if extra:
+            recs_names = [
+                (
+                    (name,) + (extras if extras else ()),
+                    (index, name, extras),
+                )
+                for index, (name, extras) in enumerate(zip(self._keys, extra))
+            ]
+        else:
+            recs_names = [
+                ((name,), (index, name, ()))
+                for index, name in enumerate(self._keys)
+            ]
+
+        self._keymap = {key: rec for keys, rec in recs_names for key in keys}
+
+        self._processors = _processors
+
+        self._key_to_index = self._make_key_to_index(self._keymap, 0)
+
+    def _has_key(self, key: object) -> bool:
+        return key in self._keymap
+
+    def _for_freeze(self) -> ResultMetaData:
+        unique_filters = self._unique_filters
+        if unique_filters and self._tuplefilter:
+            unique_filters = self._tuplefilter(unique_filters)
+
+        # TODO: are we freezing the result with or without uniqueness
+        # applied?
+        return SimpleResultMetaData(
+            self._keys,
+            extra=[self._keymap[key][2] for key in self._keys],
+            _unique_filters=unique_filters,
+        )
+
+    def __getstate__(self) -> Dict[str, Any]:
+        return {
+            "_keys": self._keys,
+            "_translated_indexes": self._translated_indexes,
+        }
+
+    def __setstate__(self, state: Dict[str, Any]) -> None:
+        if state["_translated_indexes"]:
+            _translated_indexes = state["_translated_indexes"]
+            _tuplefilter = tuplegetter(*_translated_indexes)
+        else:
+            _translated_indexes = _tuplefilter = None
+        self.__init__(  # type: ignore
+            state["_keys"],
+            _translated_indexes=_translated_indexes,
+            _tuplefilter=_tuplefilter,
+        )
+
+    def _index_for_key(self, key: Any, raiseerr: bool = True) -> int:
+        if int in key.__class__.__mro__:
+            key = self._keys[key]
+        try:
+            rec = self._keymap[key]
+        except KeyError as ke:
+            rec = self._key_fallback(key, ke, raiseerr)
+
+        return rec[0]  # type: ignore[no-any-return]
+
+    def _indexes_for_keys(self, keys: Sequence[Any]) -> Sequence[int]:
+        return [self._keymap[key][0] for key in keys]
+
+    def _metadata_for_keys(
+        self, keys: Sequence[Any]
+    ) -> Iterator[_KeyMapRecType]:
+        for key in keys:
+            if int in key.__class__.__mro__:
+                key = self._keys[key]
+
+            try:
+                rec = self._keymap[key]
+            except KeyError as ke:
+                rec = self._key_fallback(key, ke, True)
+
+            yield rec
+
+    def _reduce(self, keys: Sequence[Any]) -> ResultMetaData:
+        try:
+            metadata_for_keys = [
+                self._keymap[
+                    self._keys[key] if int in key.__class__.__mro__ else key
+                ]
+                for key in keys
+            ]
+        except KeyError as ke:
+            self._key_fallback(ke.args[0], ke, True)
+
+        indexes: Sequence[int]
+        new_keys: Sequence[str]
+        extra: Sequence[Any]
+        indexes, new_keys, extra = zip(*metadata_for_keys)
+
+        if self._translated_indexes:
+            indexes = [self._translated_indexes[idx] for idx in indexes]
+
+        tup = tuplegetter(*indexes)
+
+        new_metadata = SimpleResultMetaData(
+            new_keys,
+            extra=extra,
+            _tuplefilter=tup,
+            _translated_indexes=indexes,
+            _processors=self._processors,
+            _unique_filters=self._unique_filters,
+        )
+
+        return new_metadata
+
+
+def result_tuple(
+    fields: Sequence[str], extra: Optional[Any] = None
+) -> Callable[[Iterable[Any]], Row[Any]]:
+    parent = SimpleResultMetaData(fields, extra)
+    return functools.partial(
+        Row, parent, parent._effective_processors, parent._key_to_index
+    )
+
+
+# a symbol that indicates to internal Result methods that
+# "no row is returned".  We can't use None for those cases where a scalar
+# filter is applied to rows.
+class _NoRow(Enum):
+    _NO_ROW = 0
+
+
+_NO_ROW = _NoRow._NO_ROW
+
+
+class ResultInternal(InPlaceGenerative, Generic[_R]):
+    __slots__ = ()
+
+    _real_result: Optional[Result[Any]] = None
+    _generate_rows: bool = True
+    _row_logging_fn: Optional[Callable[[Any], Any]]
+
+    _unique_filter_state: Optional[_UniqueFilterStateType] = None
+    _post_creational_filter: Optional[Callable[[Any], Any]] = None
+    _is_cursor = False
+
+    _metadata: ResultMetaData
+
+    _source_supports_scalars: bool
+
+    def _fetchiter_impl(self) -> Iterator[_InterimRowType[Row[Any]]]:
+        raise NotImplementedError()
+
+    def _fetchone_impl(
+        self, hard_close: bool = False
+    ) -> Optional[_InterimRowType[Row[Any]]]:
+        raise NotImplementedError()
+
+    def _fetchmany_impl(
+        self, size: Optional[int] = None
+    ) -> List[_InterimRowType[Row[Any]]]:
+        raise NotImplementedError()
+
+    def _fetchall_impl(self) -> List[_InterimRowType[Row[Any]]]:
+        raise NotImplementedError()
+
+    def _soft_close(self, hard: bool = False) -> None:
+        raise NotImplementedError()
+
+    @HasMemoized_ro_memoized_attribute
+    def _row_getter(self) -> Optional[Callable[..., _R]]:
+        real_result: Result[Any] = (
+            self._real_result
+            if self._real_result
+            else cast("Result[Any]", self)
+        )
+
+        if real_result._source_supports_scalars:
+            if not self._generate_rows:
+                return None
+            else:
+                _proc = Row
+
+                def process_row(
+                    metadata: ResultMetaData,
+                    processors: Optional[_ProcessorsType],
+                    key_to_index: Mapping[_KeyType, int],
+                    scalar_obj: Any,
+                ) -> Row[Any]:
+                    return _proc(
+                        metadata, processors, key_to_index, (scalar_obj,)
+                    )
+
+        else:
+            process_row = Row  # type: ignore
+
+        metadata = self._metadata
+
+        key_to_index = metadata._key_to_index
+        processors = metadata._effective_processors
+        tf = metadata._tuplefilter
+
+        if tf and not real_result._source_supports_scalars:
+            if processors:
+                processors = tf(processors)
+
+            _make_row_orig: Callable[..., _R] = functools.partial(  # type: ignore  # noqa E501
+                process_row, metadata, processors, key_to_index
+            )
+
+            fixed_tf = tf
+
+            def make_row(row: _InterimRowType[Row[Any]]) -> _R:
+                return _make_row_orig(fixed_tf(row))
+
+        else:
+            make_row = functools.partial(  # type: ignore
+                process_row, metadata, processors, key_to_index
+            )
+
+        if real_result._row_logging_fn:
+            _log_row = real_result._row_logging_fn
+            _make_row = make_row
+
+            def make_row(row: _InterimRowType[Row[Any]]) -> _R:
+                return _log_row(_make_row(row))  # type: ignore
+
+        return make_row
+
+    @HasMemoized_ro_memoized_attribute
+    def _iterator_getter(self) -> Callable[..., Iterator[_R]]:
+        make_row = self._row_getter
+
+        post_creational_filter = self._post_creational_filter
+
+        if self._unique_filter_state:
+            uniques, strategy = self._unique_strategy
+
+            def iterrows(self: Result[Any]) -> Iterator[_R]:
+                for raw_row in self._fetchiter_impl():
+                    obj: _InterimRowType[Any] = (
+                        make_row(raw_row) if make_row else raw_row
+                    )
+                    hashed = strategy(obj) if strategy else obj
+                    if hashed in uniques:
+                        continue
+                    uniques.add(hashed)
+                    if post_creational_filter:
+                        obj = post_creational_filter(obj)
+                    yield obj  # type: ignore
+
+        else:
+
+            def iterrows(self: Result[Any]) -> Iterator[_R]:
+                for raw_row in self._fetchiter_impl():
+                    row: _InterimRowType[Any] = (
+                        make_row(raw_row) if make_row else raw_row
+                    )
+                    if post_creational_filter:
+                        row = post_creational_filter(row)
+                    yield row  # type: ignore
+
+        return iterrows
+
+    def _raw_all_rows(self) -> List[_R]:
+        make_row = self._row_getter
+        assert make_row is not None
+        rows = self._fetchall_impl()
+        return [make_row(row) for row in rows]
+
+    def _allrows(self) -> List[_R]:
+        post_creational_filter = self._post_creational_filter
+
+        make_row = self._row_getter
+
+        rows = self._fetchall_impl()
+        made_rows: List[_InterimRowType[_R]]
+        if make_row:
+            made_rows = [make_row(row) for row in rows]
+        else:
+            made_rows = rows  # type: ignore
+
+        interim_rows: List[_R]
+
+        if self._unique_filter_state:
+            uniques, strategy = self._unique_strategy
+
+            interim_rows = [
+                made_row  # type: ignore
+                for made_row, sig_row in [
+                    (
+                        made_row,
+                        strategy(made_row) if strategy else made_row,
+                    )
+                    for made_row in made_rows
+                ]
+                if sig_row not in uniques and not uniques.add(sig_row)  # type: ignore # noqa: E501
+            ]
+        else:
+            interim_rows = made_rows  # type: ignore
+
+        if post_creational_filter:
+            interim_rows = [
+                post_creational_filter(row) for row in interim_rows
+            ]
+        return interim_rows
+
+    @HasMemoized_ro_memoized_attribute
+    def _onerow_getter(
+        self,
+    ) -> Callable[..., Union[Literal[_NoRow._NO_ROW], _R]]:
+        make_row = self._row_getter
+
+        post_creational_filter = self._post_creational_filter
+
+        if self._unique_filter_state:
+            uniques, strategy = self._unique_strategy
+
+            def onerow(self: Result[Any]) -> Union[_NoRow, _R]:
+                _onerow = self._fetchone_impl
+                while True:
+                    row = _onerow()
+                    if row is None:
+                        return _NO_ROW
+                    else:
+                        obj: _InterimRowType[Any] = (
+                            make_row(row) if make_row else row
+                        )
+                        hashed = strategy(obj) if strategy else obj
+                        if hashed in uniques:
+                            continue
+                        else:
+                            uniques.add(hashed)
+                        if post_creational_filter:
+                            obj = post_creational_filter(obj)
+                        return obj  # type: ignore
+
+        else:
+
+            def onerow(self: Result[Any]) -> Union[_NoRow, _R]:
+                row = self._fetchone_impl()
+                if row is None:
+                    return _NO_ROW
+                else:
+                    interim_row: _InterimRowType[Any] = (
+                        make_row(row) if make_row else row
+                    )
+                    if post_creational_filter:
+                        interim_row = post_creational_filter(interim_row)
+                    return interim_row  # type: ignore
+
+        return onerow
+
+    @HasMemoized_ro_memoized_attribute
+    def _manyrow_getter(self) -> Callable[..., List[_R]]:
+        make_row = self._row_getter
+
+        post_creational_filter = self._post_creational_filter
+
+        if self._unique_filter_state:
+            uniques, strategy = self._unique_strategy
+
+            def filterrows(
+                make_row: Optional[Callable[..., _R]],
+                rows: List[Any],
+                strategy: Optional[Callable[[List[Any]], Any]],
+                uniques: Set[Any],
+            ) -> List[_R]:
+                if make_row:
+                    rows = [make_row(row) for row in rows]
+
+                if strategy:
+                    made_rows = (
+                        (made_row, strategy(made_row)) for made_row in rows
+                    )
+                else:
+                    made_rows = ((made_row, made_row) for made_row in rows)
+                return [
+                    made_row
+                    for made_row, sig_row in made_rows
+                    if sig_row not in uniques and not uniques.add(sig_row)  # type: ignore  # noqa: E501
+                ]
+
+            def manyrows(
+                self: ResultInternal[_R], num: Optional[int]
+            ) -> List[_R]:
+                collect: List[_R] = []
+
+                _manyrows = self._fetchmany_impl
+
+                if num is None:
+                    # if None is passed, we don't know the default
+                    # manyrows number, DBAPI has this as cursor.arraysize
+                    # different DBAPIs / fetch strategies may be different.
+                    # do a fetch to find what the number is.  if there are
+                    # only fewer rows left, then it doesn't matter.
+                    real_result = (
+                        self._real_result
+                        if self._real_result
+                        else cast("Result[Any]", self)
+                    )
+                    if real_result._yield_per:
+                        num_required = num = real_result._yield_per
+                    else:
+                        rows = _manyrows(num)
+                        num = len(rows)
+                        assert make_row is not None
+                        collect.extend(
+                            filterrows(make_row, rows, strategy, uniques)
+                        )
+                        num_required = num - len(collect)
+                else:
+                    num_required = num
+
+                assert num is not None
+
+                while num_required:
+                    rows = _manyrows(num_required)
+                    if not rows:
+                        break
+
+                    collect.extend(
+                        filterrows(make_row, rows, strategy, uniques)
+                    )
+                    num_required = num - len(collect)
+
+                if post_creational_filter:
+                    collect = [post_creational_filter(row) for row in collect]
+                return collect
+
+        else:
+
+            def manyrows(
+                self: ResultInternal[_R], num: Optional[int]
+            ) -> List[_R]:
+                if num is None:
+                    real_result = (
+                        self._real_result
+                        if self._real_result
+                        else cast("Result[Any]", self)
+                    )
+                    num = real_result._yield_per
+
+                rows: List[_InterimRowType[Any]] = self._fetchmany_impl(num)
+                if make_row:
+                    rows = [make_row(row) for row in rows]
+                if post_creational_filter:
+                    rows = [post_creational_filter(row) for row in rows]
+                return rows  # type: ignore
+
+        return manyrows
+
+    @overload
+    def _only_one_row(
+        self,
+        raise_for_second_row: bool,
+        raise_for_none: Literal[True],
+        scalar: bool,
+    ) -> _R: ...
+
+    @overload
+    def _only_one_row(
+        self,
+        raise_for_second_row: bool,
+        raise_for_none: bool,
+        scalar: bool,
+    ) -> Optional[_R]: ...
+
+    def _only_one_row(
+        self,
+        raise_for_second_row: bool,
+        raise_for_none: bool,
+        scalar: bool,
+    ) -> Optional[_R]:
+        onerow = self._fetchone_impl
+
+        row: Optional[_InterimRowType[Any]] = onerow(hard_close=True)
+        if row is None:
+            if raise_for_none:
+                raise exc.NoResultFound(
+                    "No row was found when one was required"
+                )
+            else:
+                return None
+
+        if scalar and self._source_supports_scalars:
+            self._generate_rows = False
+            make_row = None
+        else:
+            make_row = self._row_getter
+
+        try:
+            row = make_row(row) if make_row else row
+        except:
+            self._soft_close(hard=True)
+            raise
+
+        if raise_for_second_row:
+            if self._unique_filter_state:
+                # for no second row but uniqueness, need to essentially
+                # consume the entire result :(
+                uniques, strategy = self._unique_strategy
+
+                existing_row_hash = strategy(row) if strategy else row
+
+                while True:
+                    next_row: Any = onerow(hard_close=True)
+                    if next_row is None:
+                        next_row = _NO_ROW
+                        break
+
+                    try:
+                        next_row = make_row(next_row) if make_row else next_row
+
+                        if strategy:
+                            assert next_row is not _NO_ROW
+                            if existing_row_hash == strategy(next_row):
+                                continue
+                        elif row == next_row:
+                            continue
+                        # here, we have a row and it's different
+                        break
+                    except:
+                        self._soft_close(hard=True)
+                        raise
+            else:
+                next_row = onerow(hard_close=True)
+                if next_row is None:
+                    next_row = _NO_ROW
+
+            if next_row is not _NO_ROW:
+                self._soft_close(hard=True)
+                raise exc.MultipleResultsFound(
+                    "Multiple rows were found when exactly one was required"
+                    if raise_for_none
+                    else "Multiple rows were found when one or none "
+                    "was required"
+                )
+        else:
+            next_row = _NO_ROW
+            # if we checked for second row then that would have
+            # closed us :)
+            self._soft_close(hard=True)
+
+        if not scalar:
+            post_creational_filter = self._post_creational_filter
+            if post_creational_filter:
+                row = post_creational_filter(row)
+
+        if scalar and make_row:
+            return row[0]  # type: ignore
+        else:
+            return row  # type: ignore
+
+    def _iter_impl(self) -> Iterator[_R]:
+        return self._iterator_getter(self)
+
+    def _next_impl(self) -> _R:
+        row = self._onerow_getter(self)
+        if row is _NO_ROW:
+            raise StopIteration()
+        else:
+            return row
+
+    @_generative
+    def _column_slices(self, indexes: Sequence[_KeyIndexType]) -> Self:
+        real_result = (
+            self._real_result
+            if self._real_result
+            else cast("Result[Any]", self)
+        )
+
+        if not real_result._source_supports_scalars or len(indexes) != 1:
+            self._metadata = self._metadata._reduce(indexes)
+
+        assert self._generate_rows
+
+        return self
+
+    @HasMemoized.memoized_attribute
+    def _unique_strategy(self) -> _UniqueFilterStateType:
+        assert self._unique_filter_state is not None
+        uniques, strategy = self._unique_filter_state
+
+        real_result = (
+            self._real_result
+            if self._real_result is not None
+            else cast("Result[Any]", self)
+        )
+
+        if not strategy and self._metadata._unique_filters:
+            if (
+                real_result._source_supports_scalars
+                and not self._generate_rows
+            ):
+                strategy = self._metadata._unique_filters[0]
+            else:
+                filters = self._metadata._unique_filters
+                if self._metadata._tuplefilter:
+                    filters = self._metadata._tuplefilter(filters)
+
+                strategy = operator.methodcaller("_filter_on_values", filters)
+        return uniques, strategy
+
+
+class _WithKeys:
+    __slots__ = ()
+
+    _metadata: ResultMetaData
+
+    # used mainly to share documentation on the keys method.
+    def keys(self) -> RMKeyView:
+        """Return an iterable view which yields the string keys that would
+        be represented by each :class:`_engine.Row`.
+
+        The keys can represent the labels of the columns returned by a core
+        statement or the names of the orm classes returned by an orm
+        execution.
+
+        The view also can be tested for key containment using the Python
+        ``in`` operator, which will test both for the string keys represented
+        in the view, as well as for alternate keys such as column objects.
+
+        .. versionchanged:: 1.4 a key view object is returned rather than a
+           plain list.
+
+
+        """
+        return self._metadata.keys
+
+
+class Result(_WithKeys, ResultInternal[Row[_TP]]):
+    """Represent a set of database results.
+
+    .. versionadded:: 1.4  The :class:`_engine.Result` object provides a
+       completely updated usage model and calling facade for SQLAlchemy
+       Core and SQLAlchemy ORM.   In Core, it forms the basis of the
+       :class:`_engine.CursorResult` object which replaces the previous
+       :class:`_engine.ResultProxy` interface.   When using the ORM, a
+       higher level object called :class:`_engine.ChunkedIteratorResult`
+       is normally used.
+
+    .. note:: In SQLAlchemy 1.4 and above, this object is
+       used for ORM results returned by :meth:`_orm.Session.execute`, which can
+       yield instances of ORM mapped objects either individually or within
+       tuple-like rows. Note that the :class:`_engine.Result` object does not
+       deduplicate instances or rows automatically as is the case with the
+       legacy :class:`_orm.Query` object. For in-Python de-duplication of
+       instances or rows, use the :meth:`_engine.Result.unique` modifier
+       method.
+
+    .. seealso::
+
+        :ref:`tutorial_fetching_rows` - in the :doc:`/tutorial/index`
+
+    """
+
+    __slots__ = ("_metadata", "__dict__")
+
+    _row_logging_fn: Optional[Callable[[Row[Any]], Row[Any]]] = None
+
+    _source_supports_scalars: bool = False
+
+    _yield_per: Optional[int] = None
+
+    _attributes: util.immutabledict[Any, Any] = util.immutabledict()
+
+    def __init__(self, cursor_metadata: ResultMetaData):
+        self._metadata = cursor_metadata
+
+    def __enter__(self) -> Self:
+        return self
+
+    def __exit__(self, type_: Any, value: Any, traceback: Any) -> None:
+        self.close()
+
+    def close(self) -> None:
+        """close this :class:`_engine.Result`.
+
+        The behavior of this method is implementation specific, and is
+        not implemented by default.    The method should generally end
+        the resources in use by the result object and also cause any
+        subsequent iteration or row fetching to raise
+        :class:`.ResourceClosedError`.
+
+        .. versionadded:: 1.4.27 - ``.close()`` was previously not generally
+           available for all :class:`_engine.Result` classes, instead only
+           being available on the :class:`_engine.CursorResult` returned for
+           Core statement executions. As most other result objects, namely the
+           ones used by the ORM, are proxying a :class:`_engine.CursorResult`
+           in any case, this allows the underlying cursor result to be closed
+           from the outside facade for the case when the ORM query is using
+           the ``yield_per`` execution option where it does not immediately
+           exhaust and autoclose the database cursor.
+
+        """
+        self._soft_close(hard=True)
+
+    @property
+    def _soft_closed(self) -> bool:
+        raise NotImplementedError()
+
+    @property
+    def closed(self) -> bool:
+        """return ``True`` if this :class:`_engine.Result` reports .closed
+
+        .. versionadded:: 1.4.43
+
+        """
+        raise NotImplementedError()
+
+    @_generative
+    def yield_per(self, num: int) -> Self:
+        """Configure the row-fetching strategy to fetch ``num`` rows at a time.
+
+        This impacts the underlying behavior of the result when iterating over
+        the result object, or otherwise making use of  methods such as
+        :meth:`_engine.Result.fetchone` that return one row at a time.   Data
+        from the underlying cursor or other data source will be buffered up to
+        this many rows in memory, and the buffered collection will then be
+        yielded out one row at a time or as many rows are requested. Each time
+        the buffer clears, it will be refreshed to this many rows or as many
+        rows remain if fewer remain.
+
+        The :meth:`_engine.Result.yield_per` method is generally used in
+        conjunction with the
+        :paramref:`_engine.Connection.execution_options.stream_results`
+        execution option, which will allow the database dialect in use to make
+        use of a server side cursor, if the DBAPI supports a specific "server
+        side cursor" mode separate from its default mode of operation.
+
+        .. tip::
+
+            Consider using the
+            :paramref:`_engine.Connection.execution_options.yield_per`
+            execution option, which will simultaneously set
+            :paramref:`_engine.Connection.execution_options.stream_results`
+            to ensure the use of server side cursors, as well as automatically
+            invoke the :meth:`_engine.Result.yield_per` method to establish
+            a fixed row buffer size at once.
+
+            The :paramref:`_engine.Connection.execution_options.yield_per`
+            execution option is available for ORM operations, with
+            :class:`_orm.Session`-oriented use described at
+            :ref:`orm_queryguide_yield_per`. The Core-only version which works
+            with :class:`_engine.Connection` is new as of SQLAlchemy 1.4.40.
+
+        .. versionadded:: 1.4
+
+        :param num: number of rows to fetch each time the buffer is refilled.
+         If set to a value below 1, fetches all rows for the next buffer.
+
+        .. seealso::
+
+            :ref:`engine_stream_results` - describes Core behavior for
+            :meth:`_engine.Result.yield_per`
+
+            :ref:`orm_queryguide_yield_per` - in the :ref:`queryguide_toplevel`
+
+        """
+        self._yield_per = num
+        return self
+
+    @_generative
+    def unique(self, strategy: Optional[_UniqueFilterType] = None) -> Self:
+        """Apply unique filtering to the objects returned by this
+        :class:`_engine.Result`.
+
+        When this filter is applied with no arguments, the rows or objects
+        returned will filtered such that each row is returned uniquely. The
+        algorithm used to determine this uniqueness is by default the Python
+        hashing identity of the whole tuple.   In some cases a specialized
+        per-entity hashing scheme may be used, such as when using the ORM, a
+        scheme is applied which  works against the primary key identity of
+        returned objects.
+
+        The unique filter is applied **after all other filters**, which means
+        if the columns returned have been refined using a method such as the
+        :meth:`_engine.Result.columns` or :meth:`_engine.Result.scalars`
+        method, the uniquing is applied to **only the column or columns
+        returned**.   This occurs regardless of the order in which these
+        methods have been called upon the :class:`_engine.Result` object.
+
+        The unique filter also changes the calculus used for methods like
+        :meth:`_engine.Result.fetchmany` and :meth:`_engine.Result.partitions`.
+        When using :meth:`_engine.Result.unique`, these methods will continue
+        to yield the number of rows or objects requested, after uniquing
+        has been applied.  However, this necessarily impacts the buffering
+        behavior of the underlying cursor or datasource, such that multiple
+        underlying calls to ``cursor.fetchmany()`` may be necessary in order
+        to accumulate enough objects in order to provide a unique collection
+        of the requested size.
+
+        :param strategy: a callable that will be applied to rows or objects
+         being iterated, which should return an object that represents the
+         unique value of the row.   A Python ``set()`` is used to store
+         these identities.   If not passed, a default uniqueness strategy
+         is used which may have been assembled by the source of this
+         :class:`_engine.Result` object.
+
+        """
+        self._unique_filter_state = (set(), strategy)
+        return self
+
+    def columns(self, *col_expressions: _KeyIndexType) -> Self:
+        r"""Establish the columns that should be returned in each row.
+
+        This method may be used to limit the columns returned as well
+        as to reorder them.   The given list of expressions are normally
+        a series of integers or string key names.   They may also be
+        appropriate :class:`.ColumnElement` objects which correspond to
+        a given statement construct.
+
+        .. versionchanged:: 2.0  Due to a bug in 1.4, the
+           :meth:`_engine.Result.columns` method had an incorrect behavior
+           where calling upon the method with just one index would cause the
+           :class:`_engine.Result` object to yield scalar values rather than
+           :class:`_engine.Row` objects.   In version 2.0, this behavior
+           has been corrected such that calling upon
+           :meth:`_engine.Result.columns` with a single index will
+           produce a :class:`_engine.Result` object that continues
+           to yield :class:`_engine.Row` objects, which include
+           only a single column.
+
+        E.g.::
+
+            statement = select(table.c.x, table.c.y, table.c.z)
+            result = connection.execute(statement)
+
+            for z, y in result.columns('z', 'y'):
+                # ...
+
+
+        Example of using the column objects from the statement itself::
+
+            for z, y in result.columns(
+                    statement.selected_columns.c.z,
+                    statement.selected_columns.c.y
+            ):
+                # ...
+
+        .. versionadded:: 1.4
+
+        :param \*col_expressions: indicates columns to be returned.  Elements
+         may be integer row indexes, string column names, or appropriate
+         :class:`.ColumnElement` objects corresponding to a select construct.
+
+        :return: this :class:`_engine.Result` object with the modifications
+         given.
+
+        """
+        return self._column_slices(col_expressions)
+
+    @overload
+    def scalars(self: Result[Tuple[_T]]) -> ScalarResult[_T]: ...
+
+    @overload
+    def scalars(
+        self: Result[Tuple[_T]], index: Literal[0]
+    ) -> ScalarResult[_T]: ...
+
+    @overload
+    def scalars(self, index: _KeyIndexType = 0) -> ScalarResult[Any]: ...
+
+    def scalars(self, index: _KeyIndexType = 0) -> ScalarResult[Any]:
+        """Return a :class:`_engine.ScalarResult` filtering object which
+        will return single elements rather than :class:`_row.Row` objects.
+
+        E.g.::
+
+            >>> result = conn.execute(text("select int_id from table"))
+            >>> result.scalars().all()
+            [1, 2, 3]
+
+        When results are fetched from the :class:`_engine.ScalarResult`
+        filtering object, the single column-row that would be returned by the
+        :class:`_engine.Result` is instead returned as the column's value.
+
+        .. versionadded:: 1.4
+
+        :param index: integer or row key indicating the column to be fetched
+         from each row, defaults to ``0`` indicating the first column.
+
+        :return: a new :class:`_engine.ScalarResult` filtering object referring
+         to this :class:`_engine.Result` object.
+
+        """
+        return ScalarResult(self, index)
+
+    def _getter(
+        self, key: _KeyIndexType, raiseerr: bool = True
+    ) -> Optional[Callable[[Row[Any]], Any]]:
+        """return a callable that will retrieve the given key from a
+        :class:`_engine.Row`.
+
+        """
+        if self._source_supports_scalars:
+            raise NotImplementedError(
+                "can't use this function in 'only scalars' mode"
+            )
+        return self._metadata._getter(key, raiseerr)
+
+    def _tuple_getter(self, keys: Sequence[_KeyIndexType]) -> _TupleGetterType:
+        """return a callable that will retrieve the given keys from a
+        :class:`_engine.Row`.
+
+        """
+        if self._source_supports_scalars:
+            raise NotImplementedError(
+                "can't use this function in 'only scalars' mode"
+            )
+        return self._metadata._row_as_tuple_getter(keys)
+
+    def mappings(self) -> MappingResult:
+        """Apply a mappings filter to returned rows, returning an instance of
+        :class:`_engine.MappingResult`.
+
+        When this filter is applied, fetching rows will return
+        :class:`_engine.RowMapping` objects instead of :class:`_engine.Row`
+        objects.
+
+        .. versionadded:: 1.4
+
+        :return: a new :class:`_engine.MappingResult` filtering object
+         referring to this :class:`_engine.Result` object.
+
+        """
+
+        return MappingResult(self)
+
+    @property
+    def t(self) -> TupleResult[_TP]:
+        """Apply a "typed tuple" typing filter to returned rows.
+
+        The :attr:`_engine.Result.t` attribute is a synonym for
+        calling the :meth:`_engine.Result.tuples` method.
+
+        .. versionadded:: 2.0
+
+        """
+        return self  # type: ignore
+
+    def tuples(self) -> TupleResult[_TP]:
+        """Apply a "typed tuple" typing filter to returned rows.
+
+        This method returns the same :class:`_engine.Result` object
+        at runtime,
+        however annotates as returning a :class:`_engine.TupleResult` object
+        that will indicate to :pep:`484` typing tools that plain typed
+        ``Tuple`` instances are returned rather than rows.  This allows
+        tuple unpacking and ``__getitem__`` access of :class:`_engine.Row`
+        objects to by typed, for those cases where the statement invoked
+        itself included typing information.
+
+        .. versionadded:: 2.0
+
+        :return: the :class:`_engine.TupleResult` type at typing time.
+
+        .. seealso::
+
+            :attr:`_engine.Result.t` - shorter synonym
+
+            :attr:`_engine.Row._t` - :class:`_engine.Row` version
+
+        """
+
+        return self  # type: ignore
+
+    def _raw_row_iterator(self) -> Iterator[_RowData]:
+        """Return a safe iterator that yields raw row data.
+
+        This is used by the :meth:`_engine.Result.merge` method
+        to merge multiple compatible results together.
+
+        """
+        raise NotImplementedError()
+
+    def __iter__(self) -> Iterator[Row[_TP]]:
+        return self._iter_impl()
+
+    def __next__(self) -> Row[_TP]:
+        return self._next_impl()
+
+    def partitions(
+        self, size: Optional[int] = None
+    ) -> Iterator[Sequence[Row[_TP]]]:
+        """Iterate through sub-lists of rows of the size given.
+
+        Each list will be of the size given, excluding the last list to
+        be yielded, which may have a small number of rows.  No empty
+        lists will be yielded.
+
+        The result object is automatically closed when the iterator
+        is fully consumed.
+
+        Note that the backend driver will usually buffer the entire result
+        ahead of time unless the
+        :paramref:`.Connection.execution_options.stream_results` execution
+        option is used indicating that the driver should not pre-buffer
+        results, if possible.   Not all drivers support this option and
+        the option is silently ignored for those who do not.
+
+        When using the ORM, the :meth:`_engine.Result.partitions` method
+        is typically more effective from a memory perspective when it is
+        combined with use of the
+        :ref:`yield_per execution option <orm_queryguide_yield_per>`,
+        which instructs both the DBAPI driver to use server side cursors,
+        if available, as well as instructs the ORM loading internals to only
+        build a certain amount of ORM objects from a result at a time before
+        yielding them out.
+
+        .. versionadded:: 1.4
+
+        :param size: indicate the maximum number of rows to be present
+         in each list yielded.  If None, makes use of the value set by
+         the :meth:`_engine.Result.yield_per`, method, if it were called,
+         or the :paramref:`_engine.Connection.execution_options.yield_per`
+         execution option, which is equivalent in this regard.  If
+         yield_per weren't set, it makes use of the
+         :meth:`_engine.Result.fetchmany` default, which may be backend
+         specific and not well defined.
+
+        :return: iterator of lists
+
+        .. seealso::
+
+            :ref:`engine_stream_results`
+
+            :ref:`orm_queryguide_yield_per` - in the :ref:`queryguide_toplevel`
+
+        """
+
+        getter = self._manyrow_getter
+
+        while True:
+            partition = getter(self, size)
+            if partition:
+                yield partition
+            else:
+                break
+
+    def fetchall(self) -> Sequence[Row[_TP]]:
+        """A synonym for the :meth:`_engine.Result.all` method."""
+
+        return self._allrows()
+
+    def fetchone(self) -> Optional[Row[_TP]]:
+        """Fetch one row.
+
+        When all rows are exhausted, returns None.
+
+        This method is provided for backwards compatibility with
+        SQLAlchemy 1.x.x.
+
+        To fetch the first row of a result only, use the
+        :meth:`_engine.Result.first` method.  To iterate through all
+        rows, iterate the :class:`_engine.Result` object directly.
+
+        :return: a :class:`_engine.Row` object if no filters are applied,
+         or ``None`` if no rows remain.
+
+        """
+        row = self._onerow_getter(self)
+        if row is _NO_ROW:
+            return None
+        else:
+            return row
+
+    def fetchmany(self, size: Optional[int] = None) -> Sequence[Row[_TP]]:
+        """Fetch many rows.
+
+        When all rows are exhausted, returns an empty sequence.
+
+        This method is provided for backwards compatibility with
+        SQLAlchemy 1.x.x.
+
+        To fetch rows in groups, use the :meth:`_engine.Result.partitions`
+        method.
+
+        :return: a sequence of :class:`_engine.Row` objects.
+
+        .. seealso::
+
+            :meth:`_engine.Result.partitions`
+
+        """
+
+        return self._manyrow_getter(self, size)
+
+    def all(self) -> Sequence[Row[_TP]]:
+        """Return all rows in a sequence.
+
+        Closes the result set after invocation.   Subsequent invocations
+        will return an empty sequence.
+
+        .. versionadded:: 1.4
+
+        :return: a sequence of :class:`_engine.Row` objects.
+
+        .. seealso::
+
+            :ref:`engine_stream_results` - How to stream a large result set
+            without loading it completely in python.
+
+        """
+
+        return self._allrows()
+
+    def first(self) -> Optional[Row[_TP]]:
+        """Fetch the first row or ``None`` if no row is present.
+
+        Closes the result set and discards remaining rows.
+
+        .. note::  This method returns one **row**, e.g. tuple, by default.
+           To return exactly one single scalar value, that is, the first
+           column of the first row, use the
+           :meth:`_engine.Result.scalar` method,
+           or combine :meth:`_engine.Result.scalars` and
+           :meth:`_engine.Result.first`.
+
+           Additionally, in contrast to the behavior of the legacy  ORM
+           :meth:`_orm.Query.first` method, **no limit is applied** to the
+           SQL query which was invoked to produce this
+           :class:`_engine.Result`;
+           for a DBAPI driver that buffers results in memory before yielding
+           rows, all rows will be sent to the Python process and all but
+           the first row will be discarded.
+
+           .. seealso::
+
+                :ref:`migration_20_unify_select`
+
+        :return: a :class:`_engine.Row` object, or None
+         if no rows remain.
+
+        .. seealso::
+
+            :meth:`_engine.Result.scalar`
+
+            :meth:`_engine.Result.one`
+
+        """
+
+        return self._only_one_row(
+            raise_for_second_row=False, raise_for_none=False, scalar=False
+        )
+
+    def one_or_none(self) -> Optional[Row[_TP]]:
+        """Return at most one result or raise an exception.
+
+        Returns ``None`` if the result has no rows.
+        Raises :class:`.MultipleResultsFound`
+        if multiple rows are returned.
+
+        .. versionadded:: 1.4
+
+        :return: The first :class:`_engine.Row` or ``None`` if no row
+         is available.
+
+        :raises: :class:`.MultipleResultsFound`
+
+        .. seealso::
+
+            :meth:`_engine.Result.first`
+
+            :meth:`_engine.Result.one`
+
+        """
+        return self._only_one_row(
+            raise_for_second_row=True, raise_for_none=False, scalar=False
+        )
+
+    @overload
+    def scalar_one(self: Result[Tuple[_T]]) -> _T: ...
+
+    @overload
+    def scalar_one(self) -> Any: ...
+
+    def scalar_one(self) -> Any:
+        """Return exactly one scalar result or raise an exception.
+
+        This is equivalent to calling :meth:`_engine.Result.scalars` and
+        then :meth:`_engine.Result.one`.
+
+        .. seealso::
+
+            :meth:`_engine.Result.one`
+
+            :meth:`_engine.Result.scalars`
+
+        """
+        return self._only_one_row(
+            raise_for_second_row=True, raise_for_none=True, scalar=True
+        )
+
+    @overload
+    def scalar_one_or_none(self: Result[Tuple[_T]]) -> Optional[_T]: ...
+
+    @overload
+    def scalar_one_or_none(self) -> Optional[Any]: ...
+
+    def scalar_one_or_none(self) -> Optional[Any]:
+        """Return exactly one scalar result or ``None``.
+
+        This is equivalent to calling :meth:`_engine.Result.scalars` and
+        then :meth:`_engine.Result.one_or_none`.
+
+        .. seealso::
+
+            :meth:`_engine.Result.one_or_none`
+
+            :meth:`_engine.Result.scalars`
+
+        """
+        return self._only_one_row(
+            raise_for_second_row=True, raise_for_none=False, scalar=True
+        )
+
+    def one(self) -> Row[_TP]:
+        """Return exactly one row or raise an exception.
+
+        Raises :class:`.NoResultFound` if the result returns no
+        rows, or :class:`.MultipleResultsFound` if multiple rows
+        would be returned.
+
+        .. note::  This method returns one **row**, e.g. tuple, by default.
+           To return exactly one single scalar value, that is, the first
+           column of the first row, use the
+           :meth:`_engine.Result.scalar_one` method, or combine
+           :meth:`_engine.Result.scalars` and
+           :meth:`_engine.Result.one`.
+
+        .. versionadded:: 1.4
+
+        :return: The first :class:`_engine.Row`.
+
+        :raises: :class:`.MultipleResultsFound`, :class:`.NoResultFound`
+
+        .. seealso::
+
+            :meth:`_engine.Result.first`
+
+            :meth:`_engine.Result.one_or_none`
+
+            :meth:`_engine.Result.scalar_one`
+
+        """
+        return self._only_one_row(
+            raise_for_second_row=True, raise_for_none=True, scalar=False
+        )
+
+    @overload
+    def scalar(self: Result[Tuple[_T]]) -> Optional[_T]: ...
+
+    @overload
+    def scalar(self) -> Any: ...
+
+    def scalar(self) -> Any:
+        """Fetch the first column of the first row, and close the result set.
+
+        Returns ``None`` if there are no rows to fetch.
+
+        No validation is performed to test if additional rows remain.
+
+        After calling this method, the object is fully closed,
+        e.g. the :meth:`_engine.CursorResult.close`
+        method will have been called.
+
+        :return: a Python scalar value, or ``None`` if no rows remain.
+
+        """
+        return self._only_one_row(
+            raise_for_second_row=False, raise_for_none=False, scalar=True
+        )
+
+    def freeze(self) -> FrozenResult[_TP]:
+        """Return a callable object that will produce copies of this
+        :class:`_engine.Result` when invoked.
+
+        The callable object returned is an instance of
+        :class:`_engine.FrozenResult`.
+
+        This is used for result set caching.  The method must be called
+        on the result when it has been unconsumed, and calling the method
+        will consume the result fully.   When the :class:`_engine.FrozenResult`
+        is retrieved from a cache, it can be called any number of times where
+        it will produce a new :class:`_engine.Result` object each time
+        against its stored set of rows.
+
+        .. seealso::
+
+            :ref:`do_orm_execute_re_executing` - example usage within the
+            ORM to implement a result-set cache.
+
+        """
+
+        return FrozenResult(self)
+
+    def merge(self, *others: Result[Any]) -> MergedResult[_TP]:
+        """Merge this :class:`_engine.Result` with other compatible result
+        objects.
+
+        The object returned is an instance of :class:`_engine.MergedResult`,
+        which will be composed of iterators from the given result
+        objects.
+
+        The new result will use the metadata from this result object.
+        The subsequent result objects must be against an identical
+        set of result / cursor metadata, otherwise the behavior is
+        undefined.
+
+        """
+        return MergedResult(self._metadata, (self,) + others)
+
+
+class FilterResult(ResultInternal[_R]):
+    """A wrapper for a :class:`_engine.Result` that returns objects other than
+    :class:`_engine.Row` objects, such as dictionaries or scalar objects.
+
+    :class:`_engine.FilterResult` is the common base for additional result
+    APIs including :class:`_engine.MappingResult`,
+    :class:`_engine.ScalarResult` and :class:`_engine.AsyncResult`.
+
+    """
+
+    __slots__ = (
+        "_real_result",
+        "_post_creational_filter",
+        "_metadata",
+        "_unique_filter_state",
+        "__dict__",
+    )
+
+    _post_creational_filter: Optional[Callable[[Any], Any]]
+
+    _real_result: Result[Any]
+
+    def __enter__(self) -> Self:
+        return self
+
+    def __exit__(self, type_: Any, value: Any, traceback: Any) -> None:
+        self._real_result.__exit__(type_, value, traceback)
+
+    @_generative
+    def yield_per(self, num: int) -> Self:
+        """Configure the row-fetching strategy to fetch ``num`` rows at a time.
+
+        The :meth:`_engine.FilterResult.yield_per` method is a pass through
+        to the :meth:`_engine.Result.yield_per` method.  See that method's
+        documentation for usage notes.
+
+        .. versionadded:: 1.4.40 - added :meth:`_engine.FilterResult.yield_per`
+           so that the method is available on all result set implementations
+
+        .. seealso::
+
+            :ref:`engine_stream_results` - describes Core behavior for
+            :meth:`_engine.Result.yield_per`
+
+            :ref:`orm_queryguide_yield_per` - in the :ref:`queryguide_toplevel`
+
+        """
+        self._real_result = self._real_result.yield_per(num)
+        return self
+
+    def _soft_close(self, hard: bool = False) -> None:
+        self._real_result._soft_close(hard=hard)
+
+    @property
+    def _soft_closed(self) -> bool:
+        return self._real_result._soft_closed
+
+    @property
+    def closed(self) -> bool:
+        """Return ``True`` if the underlying :class:`_engine.Result` reports
+        closed
+
+        .. versionadded:: 1.4.43
+
+        """
+        return self._real_result.closed
+
+    def close(self) -> None:
+        """Close this :class:`_engine.FilterResult`.
+
+        .. versionadded:: 1.4.43
+
+        """
+        self._real_result.close()
+
+    @property
+    def _attributes(self) -> Dict[Any, Any]:
+        return self._real_result._attributes
+
+    def _fetchiter_impl(self) -> Iterator[_InterimRowType[Row[Any]]]:
+        return self._real_result._fetchiter_impl()
+
+    def _fetchone_impl(
+        self, hard_close: bool = False
+    ) -> Optional[_InterimRowType[Row[Any]]]:
+        return self._real_result._fetchone_impl(hard_close=hard_close)
+
+    def _fetchall_impl(self) -> List[_InterimRowType[Row[Any]]]:
+        return self._real_result._fetchall_impl()
+
+    def _fetchmany_impl(
+        self, size: Optional[int] = None
+    ) -> List[_InterimRowType[Row[Any]]]:
+        return self._real_result._fetchmany_impl(size=size)
+
+
+class ScalarResult(FilterResult[_R]):
+    """A wrapper for a :class:`_engine.Result` that returns scalar values
+    rather than :class:`_row.Row` values.
+
+    The :class:`_engine.ScalarResult` object is acquired by calling the
+    :meth:`_engine.Result.scalars` method.
+
+    A special limitation of :class:`_engine.ScalarResult` is that it has
+    no ``fetchone()`` method; since the semantics of ``fetchone()`` are that
+    the ``None`` value indicates no more results, this is not compatible
+    with :class:`_engine.ScalarResult` since there is no way to distinguish
+    between ``None`` as a row value versus ``None`` as an indicator.  Use
+    ``next(result)`` to receive values individually.
+
+    """
+
+    __slots__ = ()
+
+    _generate_rows = False
+
+    _post_creational_filter: Optional[Callable[[Any], Any]]
+
+    def __init__(self, real_result: Result[Any], index: _KeyIndexType):
+        self._real_result = real_result
+
+        if real_result._source_supports_scalars:
+            self._metadata = real_result._metadata
+            self._post_creational_filter = None
+        else:
+            self._metadata = real_result._metadata._reduce([index])
+            self._post_creational_filter = operator.itemgetter(0)
+
+        self._unique_filter_state = real_result._unique_filter_state
+
+    def unique(self, strategy: Optional[_UniqueFilterType] = None) -> Self:
+        """Apply unique filtering to the objects returned by this
+        :class:`_engine.ScalarResult`.
+
+        See :meth:`_engine.Result.unique` for usage details.
+
+        """
+        self._unique_filter_state = (set(), strategy)
+        return self
+
+    def partitions(self, size: Optional[int] = None) -> Iterator[Sequence[_R]]:
+        """Iterate through sub-lists of elements of the size given.
+
+        Equivalent to :meth:`_engine.Result.partitions` except that
+        scalar values, rather than :class:`_engine.Row` objects,
+        are returned.
+
+        """
+
+        getter = self._manyrow_getter
+
+        while True:
+            partition = getter(self, size)
+            if partition:
+                yield partition
+            else:
+                break
+
+    def fetchall(self) -> Sequence[_R]:
+        """A synonym for the :meth:`_engine.ScalarResult.all` method."""
+
+        return self._allrows()
+
+    def fetchmany(self, size: Optional[int] = None) -> Sequence[_R]:
+        """Fetch many objects.
+
+        Equivalent to :meth:`_engine.Result.fetchmany` except that
+        scalar values, rather than :class:`_engine.Row` objects,
+        are returned.
+
+        """
+        return self._manyrow_getter(self, size)
+
+    def all(self) -> Sequence[_R]:
+        """Return all scalar values in a sequence.
+
+        Equivalent to :meth:`_engine.Result.all` except that
+        scalar values, rather than :class:`_engine.Row` objects,
+        are returned.
+
+        """
+        return self._allrows()
+
+    def __iter__(self) -> Iterator[_R]:
+        return self._iter_impl()
+
+    def __next__(self) -> _R:
+        return self._next_impl()
+
+    def first(self) -> Optional[_R]:
+        """Fetch the first object or ``None`` if no object is present.
+
+        Equivalent to :meth:`_engine.Result.first` except that
+        scalar values, rather than :class:`_engine.Row` objects,
+        are returned.
+
+
+        """
+        return self._only_one_row(
+            raise_for_second_row=False, raise_for_none=False, scalar=False
+        )
+
+    def one_or_none(self) -> Optional[_R]:
+        """Return at most one object or raise an exception.
+
+        Equivalent to :meth:`_engine.Result.one_or_none` except that
+        scalar values, rather than :class:`_engine.Row` objects,
+        are returned.
+
+        """
+        return self._only_one_row(
+            raise_for_second_row=True, raise_for_none=False, scalar=False
+        )
+
+    def one(self) -> _R:
+        """Return exactly one object or raise an exception.
+
+        Equivalent to :meth:`_engine.Result.one` except that
+        scalar values, rather than :class:`_engine.Row` objects,
+        are returned.
+
+        """
+        return self._only_one_row(
+            raise_for_second_row=True, raise_for_none=True, scalar=False
+        )
+
+
+class TupleResult(FilterResult[_R], util.TypingOnly):
+    """A :class:`_engine.Result` that's typed as returning plain
+    Python tuples instead of rows.
+
+    Since :class:`_engine.Row` acts like a tuple in every way already,
+    this class is a typing only class, regular :class:`_engine.Result` is
+    still used at runtime.
+
+    """
+
+    __slots__ = ()
+
+    if TYPE_CHECKING:
+
+        def partitions(
+            self, size: Optional[int] = None
+        ) -> Iterator[Sequence[_R]]:
+            """Iterate through sub-lists of elements of the size given.
+
+            Equivalent to :meth:`_engine.Result.partitions` except that
+            tuple values, rather than :class:`_engine.Row` objects,
+            are returned.
+
+            """
+            ...
+
+        def fetchone(self) -> Optional[_R]:
+            """Fetch one tuple.
+
+            Equivalent to :meth:`_engine.Result.fetchone` except that
+            tuple values, rather than :class:`_engine.Row`
+            objects, are returned.
+
+            """
+            ...
+
+        def fetchall(self) -> Sequence[_R]:
+            """A synonym for the :meth:`_engine.ScalarResult.all` method."""
+            ...
+
+        def fetchmany(self, size: Optional[int] = None) -> Sequence[_R]:
+            """Fetch many objects.
+
+            Equivalent to :meth:`_engine.Result.fetchmany` except that
+            tuple values, rather than :class:`_engine.Row` objects,
+            are returned.
+
+            """
+            ...
+
+        def all(self) -> Sequence[_R]:  # noqa: A001
+            """Return all scalar values in a sequence.
+
+            Equivalent to :meth:`_engine.Result.all` except that
+            tuple values, rather than :class:`_engine.Row` objects,
+            are returned.
+
+            """
+            ...
+
+        def __iter__(self) -> Iterator[_R]: ...
+
+        def __next__(self) -> _R: ...
+
+        def first(self) -> Optional[_R]:
+            """Fetch the first object or ``None`` if no object is present.
+
+            Equivalent to :meth:`_engine.Result.first` except that
+            tuple values, rather than :class:`_engine.Row` objects,
+            are returned.
+
+
+            """
+            ...
+
+        def one_or_none(self) -> Optional[_R]:
+            """Return at most one object or raise an exception.
+
+            Equivalent to :meth:`_engine.Result.one_or_none` except that
+            tuple values, rather than :class:`_engine.Row` objects,
+            are returned.
+
+            """
+            ...
+
+        def one(self) -> _R:
+            """Return exactly one object or raise an exception.
+
+            Equivalent to :meth:`_engine.Result.one` except that
+            tuple values, rather than :class:`_engine.Row` objects,
+            are returned.
+
+            """
+            ...
+
+        @overload
+        def scalar_one(self: TupleResult[Tuple[_T]]) -> _T: ...
+
+        @overload
+        def scalar_one(self) -> Any: ...
+
+        def scalar_one(self) -> Any:
+            """Return exactly one scalar result or raise an exception.
+
+            This is equivalent to calling :meth:`_engine.Result.scalars`
+            and then :meth:`_engine.Result.one`.
+
+            .. seealso::
+
+                :meth:`_engine.Result.one`
+
+                :meth:`_engine.Result.scalars`
+
+            """
+            ...
+
+        @overload
+        def scalar_one_or_none(
+            self: TupleResult[Tuple[_T]],
+        ) -> Optional[_T]: ...
+
+        @overload
+        def scalar_one_or_none(self) -> Optional[Any]: ...
+
+        def scalar_one_or_none(self) -> Optional[Any]:
+            """Return exactly one or no scalar result.
+
+            This is equivalent to calling :meth:`_engine.Result.scalars`
+            and then :meth:`_engine.Result.one_or_none`.
+
+            .. seealso::
+
+                :meth:`_engine.Result.one_or_none`
+
+                :meth:`_engine.Result.scalars`
+
+            """
+            ...
+
+        @overload
+        def scalar(self: TupleResult[Tuple[_T]]) -> Optional[_T]: ...
+
+        @overload
+        def scalar(self) -> Any: ...
+
+        def scalar(self) -> Any:
+            """Fetch the first column of the first row, and close the result
+            set.
+
+            Returns ``None`` if there are no rows to fetch.
+
+            No validation is performed to test if additional rows remain.
+
+            After calling this method, the object is fully closed,
+            e.g. the :meth:`_engine.CursorResult.close`
+            method will have been called.
+
+            :return: a Python scalar value , or ``None`` if no rows remain.
+
+            """
+            ...
+
+
+class MappingResult(_WithKeys, FilterResult[RowMapping]):
+    """A wrapper for a :class:`_engine.Result` that returns dictionary values
+    rather than :class:`_engine.Row` values.
+
+    The :class:`_engine.MappingResult` object is acquired by calling the
+    :meth:`_engine.Result.mappings` method.
+
+    """
+
+    __slots__ = ()
+
+    _generate_rows = True
+
+    _post_creational_filter = operator.attrgetter("_mapping")
+
+    def __init__(self, result: Result[Any]):
+        self._real_result = result
+        self._unique_filter_state = result._unique_filter_state
+        self._metadata = result._metadata
+        if result._source_supports_scalars:
+            self._metadata = self._metadata._reduce([0])
+
+    def unique(self, strategy: Optional[_UniqueFilterType] = None) -> Self:
+        """Apply unique filtering to the objects returned by this
+        :class:`_engine.MappingResult`.
+
+        See :meth:`_engine.Result.unique` for usage details.
+
+        """
+        self._unique_filter_state = (set(), strategy)
+        return self
+
+    def columns(self, *col_expressions: _KeyIndexType) -> Self:
+        r"""Establish the columns that should be returned in each row."""
+        return self._column_slices(col_expressions)
+
+    def partitions(
+        self, size: Optional[int] = None
+    ) -> Iterator[Sequence[RowMapping]]:
+        """Iterate through sub-lists of elements of the size given.
+
+        Equivalent to :meth:`_engine.Result.partitions` except that
+        :class:`_engine.RowMapping` values, rather than :class:`_engine.Row`
+        objects, are returned.
+
+        """
+
+        getter = self._manyrow_getter
+
+        while True:
+            partition = getter(self, size)
+            if partition:
+                yield partition
+            else:
+                break
+
+    def fetchall(self) -> Sequence[RowMapping]:
+        """A synonym for the :meth:`_engine.MappingResult.all` method."""
+
+        return self._allrows()
+
+    def fetchone(self) -> Optional[RowMapping]:
+        """Fetch one object.
+
+        Equivalent to :meth:`_engine.Result.fetchone` except that
+        :class:`_engine.RowMapping` values, rather than :class:`_engine.Row`
+        objects, are returned.
+
+        """
+
+        row = self._onerow_getter(self)
+        if row is _NO_ROW:
+            return None
+        else:
+            return row
+
+    def fetchmany(self, size: Optional[int] = None) -> Sequence[RowMapping]:
+        """Fetch many objects.
+
+        Equivalent to :meth:`_engine.Result.fetchmany` except that
+        :class:`_engine.RowMapping` values, rather than :class:`_engine.Row`
+        objects, are returned.
+
+        """
+
+        return self._manyrow_getter(self, size)
+
+    def all(self) -> Sequence[RowMapping]:
+        """Return all scalar values in a sequence.
+
+        Equivalent to :meth:`_engine.Result.all` except that
+        :class:`_engine.RowMapping` values, rather than :class:`_engine.Row`
+        objects, are returned.
+
+        """
+
+        return self._allrows()
+
+    def __iter__(self) -> Iterator[RowMapping]:
+        return self._iter_impl()
+
+    def __next__(self) -> RowMapping:
+        return self._next_impl()
+
+    def first(self) -> Optional[RowMapping]:
+        """Fetch the first object or ``None`` if no object is present.
+
+        Equivalent to :meth:`_engine.Result.first` except that
+        :class:`_engine.RowMapping` values, rather than :class:`_engine.Row`
+        objects, are returned.
+
+
+        """
+        return self._only_one_row(
+            raise_for_second_row=False, raise_for_none=False, scalar=False
+        )
+
+    def one_or_none(self) -> Optional[RowMapping]:
+        """Return at most one object or raise an exception.
+
+        Equivalent to :meth:`_engine.Result.one_or_none` except that
+        :class:`_engine.RowMapping` values, rather than :class:`_engine.Row`
+        objects, are returned.
+
+        """
+        return self._only_one_row(
+            raise_for_second_row=True, raise_for_none=False, scalar=False
+        )
+
+    def one(self) -> RowMapping:
+        """Return exactly one object or raise an exception.
+
+        Equivalent to :meth:`_engine.Result.one` except that
+        :class:`_engine.RowMapping` values, rather than :class:`_engine.Row`
+        objects, are returned.
+
+        """
+        return self._only_one_row(
+            raise_for_second_row=True, raise_for_none=True, scalar=False
+        )
+
+
+class FrozenResult(Generic[_TP]):
+    """Represents a :class:`_engine.Result` object in a "frozen" state suitable
+    for caching.
+
+    The :class:`_engine.FrozenResult` object is returned from the
+    :meth:`_engine.Result.freeze` method of any :class:`_engine.Result`
+    object.
+
+    A new iterable :class:`_engine.Result` object is generated from a fixed
+    set of data each time the :class:`_engine.FrozenResult` is invoked as
+    a callable::
+
+
+        result = connection.execute(query)
+
+        frozen = result.freeze()
+
+        unfrozen_result_one = frozen()
+
+        for row in unfrozen_result_one:
+            print(row)
+
+        unfrozen_result_two = frozen()
+        rows = unfrozen_result_two.all()
+
+        # ... etc
+
+    .. versionadded:: 1.4
+
+    .. seealso::
+
+        :ref:`do_orm_execute_re_executing` - example usage within the
+        ORM to implement a result-set cache.
+
+        :func:`_orm.loading.merge_frozen_result` - ORM function to merge
+        a frozen result back into a :class:`_orm.Session`.
+
+    """
+
+    data: Sequence[Any]
+
+    def __init__(self, result: Result[_TP]):
+        self.metadata = result._metadata._for_freeze()
+        self._source_supports_scalars = result._source_supports_scalars
+        self._attributes = result._attributes
+
+        if self._source_supports_scalars:
+            self.data = list(result._raw_row_iterator())
+        else:
+            self.data = result.fetchall()
+
+    def rewrite_rows(self) -> Sequence[Sequence[Any]]:
+        if self._source_supports_scalars:
+            return [[elem] for elem in self.data]
+        else:
+            return [list(row) for row in self.data]
+
+    def with_new_rows(
+        self, tuple_data: Sequence[Row[_TP]]
+    ) -> FrozenResult[_TP]:
+        fr = FrozenResult.__new__(FrozenResult)
+        fr.metadata = self.metadata
+        fr._attributes = self._attributes
+        fr._source_supports_scalars = self._source_supports_scalars
+
+        if self._source_supports_scalars:
+            fr.data = [d[0] for d in tuple_data]
+        else:
+            fr.data = tuple_data
+        return fr
+
+    def __call__(self) -> Result[_TP]:
+        result: IteratorResult[_TP] = IteratorResult(
+            self.metadata, iter(self.data)
+        )
+        result._attributes = self._attributes
+        result._source_supports_scalars = self._source_supports_scalars
+        return result
+
+
+class IteratorResult(Result[_TP]):
+    """A :class:`_engine.Result` that gets data from a Python iterator of
+    :class:`_engine.Row` objects or similar row-like data.
+
+    .. versionadded:: 1.4
+
+    """
+
+    _hard_closed = False
+    _soft_closed = False
+
+    def __init__(
+        self,
+        cursor_metadata: ResultMetaData,
+        iterator: Iterator[_InterimSupportsScalarsRowType],
+        raw: Optional[Result[Any]] = None,
+        _source_supports_scalars: bool = False,
+    ):
+        self._metadata = cursor_metadata
+        self.iterator = iterator
+        self.raw = raw
+        self._source_supports_scalars = _source_supports_scalars
+
+    @property
+    def closed(self) -> bool:
+        """Return ``True`` if this :class:`_engine.IteratorResult` has
+        been closed
+
+        .. versionadded:: 1.4.43
+
+        """
+        return self._hard_closed
+
+    def _soft_close(self, hard: bool = False, **kw: Any) -> None:
+        if hard:
+            self._hard_closed = True
+        if self.raw is not None:
+            self.raw._soft_close(hard=hard, **kw)
+        self.iterator = iter([])
+        self._reset_memoizations()
+        self._soft_closed = True
+
+    def _raise_hard_closed(self) -> NoReturn:
+        raise exc.ResourceClosedError("This result object is closed.")
+
+    def _raw_row_iterator(self) -> Iterator[_RowData]:
+        return self.iterator
+
+    def _fetchiter_impl(self) -> Iterator[_InterimSupportsScalarsRowType]:
+        if self._hard_closed:
+            self._raise_hard_closed()
+        return self.iterator
+
+    def _fetchone_impl(
+        self, hard_close: bool = False
+    ) -> Optional[_InterimRowType[Row[Any]]]:
+        if self._hard_closed:
+            self._raise_hard_closed()
+
+        row = next(self.iterator, _NO_ROW)
+        if row is _NO_ROW:
+            self._soft_close(hard=hard_close)
+            return None
+        else:
+            return row
+
+    def _fetchall_impl(self) -> List[_InterimRowType[Row[Any]]]:
+        if self._hard_closed:
+            self._raise_hard_closed()
+        try:
+            return list(self.iterator)
+        finally:
+            self._soft_close()
+
+    def _fetchmany_impl(
+        self, size: Optional[int] = None
+    ) -> List[_InterimRowType[Row[Any]]]:
+        if self._hard_closed:
+            self._raise_hard_closed()
+
+        return list(itertools.islice(self.iterator, 0, size))
+
+
+def null_result() -> IteratorResult[Any]:
+    return IteratorResult(SimpleResultMetaData([]), iter([]))
+
+
+class ChunkedIteratorResult(IteratorResult[_TP]):
+    """An :class:`_engine.IteratorResult` that works from an
+    iterator-producing callable.
+
+    The given ``chunks`` argument is a function that is given a number of rows
+    to return in each chunk, or ``None`` for all rows.  The function should
+    then return an un-consumed iterator of lists, each list of the requested
+    size.
+
+    The function can be called at any time again, in which case it should
+    continue from the same result set but adjust the chunk size as given.
+
+    .. versionadded:: 1.4
+
+    """
+
+    def __init__(
+        self,
+        cursor_metadata: ResultMetaData,
+        chunks: Callable[
+            [Optional[int]], Iterator[Sequence[_InterimRowType[_R]]]
+        ],
+        source_supports_scalars: bool = False,
+        raw: Optional[Result[Any]] = None,
+        dynamic_yield_per: bool = False,
+    ):
+        self._metadata = cursor_metadata
+        self.chunks = chunks
+        self._source_supports_scalars = source_supports_scalars
+        self.raw = raw
+        self.iterator = itertools.chain.from_iterable(self.chunks(None))
+        self.dynamic_yield_per = dynamic_yield_per
+
+    @_generative
+    def yield_per(self, num: int) -> Self:
+        # TODO: this throws away the iterator which may be holding
+        # onto a chunk.   the yield_per cannot be changed once any
+        # rows have been fetched.   either find a way to enforce this,
+        # or we can't use itertools.chain and will instead have to
+        # keep track.
+
+        self._yield_per = num
+        self.iterator = itertools.chain.from_iterable(self.chunks(num))
+        return self
+
+    def _soft_close(self, hard: bool = False, **kw: Any) -> None:
+        super()._soft_close(hard=hard, **kw)
+        self.chunks = lambda size: []  # type: ignore
+
+    def _fetchmany_impl(
+        self, size: Optional[int] = None
+    ) -> List[_InterimRowType[Row[Any]]]:
+        if self.dynamic_yield_per:
+            self.iterator = itertools.chain.from_iterable(self.chunks(size))
+        return super()._fetchmany_impl(size=size)
+
+
+class MergedResult(IteratorResult[_TP]):
+    """A :class:`_engine.Result` that is merged from any number of
+    :class:`_engine.Result` objects.
+
+    Returned by the :meth:`_engine.Result.merge` method.
+
+    .. versionadded:: 1.4
+
+    """
+
+    closed = False
+    rowcount: Optional[int]
+
+    def __init__(
+        self, cursor_metadata: ResultMetaData, results: Sequence[Result[_TP]]
+    ):
+        self._results = results
+        super().__init__(
+            cursor_metadata,
+            itertools.chain.from_iterable(
+                r._raw_row_iterator() for r in results
+            ),
+        )
+
+        self._unique_filter_state = results[0]._unique_filter_state
+        self._yield_per = results[0]._yield_per
+
+        # going to try something w/ this in next rev
+        self._source_supports_scalars = results[0]._source_supports_scalars
+
+        self._attributes = self._attributes.merge_with(
+            *[r._attributes for r in results]
+        )
+
+    def _soft_close(self, hard: bool = False, **kw: Any) -> None:
+        for r in self._results:
+            r._soft_close(hard=hard, **kw)
+        if hard:
+            self.closed = True