cx_Oracle modernize

Full "RETURNING" support is implemented for the cx_Oracle dialect, meaning
multiple RETURNING rows are now recived for DML statements that produce
more than one row for RETURNING.

cx_Oracle 7 is now the minimum version for cx_Oracle.

Getting Oracle to do multirow returning took about 5 minutes.  however,
getting Oracle's RETURNING system to integrate with ORM-enabled
insert, update, delete, is a big deal because that architecture wasn't
really working very robustly, including some recent changes in 1.4
for FromStatement were done in a hurry, so this patch also cleans up
the FromStatement situation and begins to establish it more concretely
as the base for all ReturnsRows / TextClause ORM scenarios.

Fixes: #6245
Change-Id: I2b4e6007affa51ce311d2d5baa3917f356ab961f

1 files changed, 1 insertions, 91 deletions

diff --git a/lib/sqlalchemy/orm/query.py b/lib/sqlalchemy/orm/query.py
index b9ced44d5..a754bd4f2 100644
--- a/lib/sqlalchemy/orm/query.py
+++ b/lib/sqlalchemy/orm/query.py
@@ -21,7 +21,6 @@ database to return iterable result sets.
 from __future__ import annotations
 
 import collections.abc as collections_abc
-import itertools
 import operator
 from typing import Any
 from typing import Generic
@@ -40,9 +39,9 @@ from .base import _assertions
 from .context import _column_descriptions
 from .context import _determine_last_joined_entity
 from .context import _legacy_filter_by_entity_zero
+from .context import FromStatement
 from .context import LABEL_STYLE_LEGACY_ORM
 from .context import ORMCompileState
-from .context import ORMFromStatementCompileState
 from .context import QueryContext
 from .interfaces import ORMColumnDescription
 from .interfaces import ORMColumnsClauseRole
@@ -71,14 +70,10 @@ from ..sql.expression import Exists
 from ..sql.selectable import _MemoizedSelectEntities
 from ..sql.selectable import _SelectFromElements
 from ..sql.selectable import ForUpdateArg
-from ..sql.selectable import GroupedElement
 from ..sql.selectable import HasHints
 from ..sql.selectable import HasPrefixes
 from ..sql.selectable import HasSuffixes
 from ..sql.selectable import LABEL_STYLE_TABLENAME_PLUS_COL
-from ..sql.selectable import SelectBase
-from ..sql.selectable import SelectStatementGrouping
-from ..sql.visitors import InternalTraversal
 
 if TYPE_CHECKING:
     from ..sql.selectable import _SetupJoinsElement
@@ -2765,91 +2760,6 @@ class Query(
         return context
 
 
-class FromStatement(GroupedElement, SelectBase, Executable):
-    """Core construct that represents a load of ORM objects from a finished
-    select or text construct.
-
-    """
-
-    __visit_name__ = "orm_from_statement"
-
-    _compile_options = ORMFromStatementCompileState.default_compile_options
-
-    _compile_state_factory = ORMFromStatementCompileState.create_for_statement
-
-    _for_update_arg = None
-
-    _traverse_internals = [
-        ("_raw_columns", InternalTraversal.dp_clauseelement_list),
-        ("element", InternalTraversal.dp_clauseelement),
-    ] + Executable._executable_traverse_internals
-
-    _cache_key_traversal = _traverse_internals + [
-        ("_compile_options", InternalTraversal.dp_has_cache_key)
-    ]
-
-    def __init__(self, entities, element):
-        self._raw_columns = [
-            coercions.expect(
-                roles.ColumnsClauseRole,
-                ent,
-                apply_propagate_attrs=self,
-                post_inspect=True,
-            )
-            for ent in util.to_list(entities)
-        ]
-        self.element = element
-
-    def get_label_style(self):
-        return self._label_style
-
-    def set_label_style(self, label_style):
-        return SelectStatementGrouping(
-            self.element.set_label_style(label_style)
-        )
-
-    @property
-    def _label_style(self):
-        return self.element._label_style
-
-    def _compiler_dispatch(self, compiler, **kw):
-
-        """provide a fixed _compiler_dispatch method.
-
-        This is roughly similar to using the sqlalchemy.ext.compiler
-        ``@compiles`` extension.
-
-        """
-
-        compile_state = self._compile_state_factory(self, compiler, **kw)
-
-        toplevel = not compiler.stack
-
-        if toplevel:
-            compiler.compile_state = compile_state
-
-        return compiler.process(compile_state.statement, **kw)
-
-    def _ensure_disambiguated_names(self):
-        return self
-
-    def get_children(self, **kw):
-        for elem in itertools.chain.from_iterable(
-            element._from_objects for element in self._raw_columns
-        ):
-            yield elem
-        for elem in super(FromStatement, self).get_children(**kw):
-            yield elem
-
-    @property
-    def _returning(self):
-        return self.element._returning if self.element.is_dml else None
-
-    @property
-    def _inline(self):
-        return self.element._inline if self.element.is_dml else None
-
-
 class AliasOption(interfaces.LoaderOption):
     inherit_cache = False