sqlalchemy.sql.selectable._MemoizedSelectEntities

class documentation

class _MemoizedSelectEntities(cache_key.HasCacheKey, traversals.HasCopyInternals, visitors.Traversible): (source)

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represents partial state from a Select object, for the case where Select.columns() has redefined the set of columns/entities the statement will be SELECTing from. This object represents the entities from the SELECT before that transformation was applied, so that transformations that were made in terms of the SELECT at that time, such as join() as well as options(), can access the correct context. In previous SQLAlchemy versions, this wasn't needed because these constructs calculated everything up front, like when you called join() or options(), it did everything to figure out how that would translate into specific SQL constructs that would be ready to send directly to the SQL compiler when needed. But as of 1.4, all of that stuff is done in the compilation phase, during the "compile state" portion of the process, so that the work can all be cached. So it needs to be able to resolve joins/options2 based on what the list of entities was when those methods were called.

Class Variable __visit_name__ Undocumented
Class Method _generate_for_statement Undocumented
Method _clone Undocumented
Class Variable _is_clone_of Undocumented
Class Variable _traverse_internals Undocumented
Instance Variable _raw_columns Undocumented
Instance Variable _setup_joins Undocumented
Instance Variable _with_options Undocumented

Inherited from HasCacheKey:

Class Variable __slots__ Undocumented
Class Variable inherit_cache Indicate if this :class:`.HasCacheKey` instance should make use of the cache key generation scheme used by its immediate superclass.
Class Method _generate_cache_attrs generate cache key dispatcher for a new class.
Class Method _generate_cache_key_for_object Undocumented
Method _gen_cache_key return an optional cache key.
Method _generate_cache_key return a cache key.
Class Variable _generated_cache_key_traversal Undocumented
Class Variable _hierarchy_supports_caching private attribute which may be set to False to prevent the inherit_cache warning from being emitted for a hierarchy of subclasses.
Class Variable _is_has_cache_key Undocumented

Inherited from HasCopyInternals (via HasCacheKey):

Method _copy_internals Reassign internal elements to be clones of themselves.

Inherited from HasTraverseInternals (via HasCacheKey, HasCopyInternals):

Method get_children Return immediate child :class:`.visitors.HasTraverseInternals` elements of this :class:`.visitors.HasTraverseInternals`.
Class Variable _is_immutable Undocumented

Inherited from Visitable (via HasCacheKey, HasCopyInternals, HasTraverseInternals):

Method __class_getitem__ Undocumented
Method __init_subclass__ Undocumented
Class Method _generate_compiler_dispatch Undocumented
Method _compiler_dispatch Undocumented
Class Variable _original_compiler_dispatch Undocumented
__visit_name__: str = (source)
overrides sqlalchemy.sql.visitors.Visitable.__visit_name__

Undocumented

@classmethod
def _generate_for_statement(cls, select_stmt: Select[Any]): (source)

Undocumented

def _clone(self, **kw: Any) -> Self: (source)
overrides sqlalchemy.sql.traversals.HasCopyInternals._clone

Undocumented

_is_clone_of: Optional[ClauseElement] = (source)

Undocumented

_traverse_internals: _TraverseInternalsType = (source)
overrides sqlalchemy.sql.visitors.HasTraverseInternals._traverse_internals

Undocumented

_raw_columns = (source)

Undocumented

_setup_joins = (source)

Undocumented

_with_options = (source)

Undocumented