sqlalchemy.sql.expression.Alias

class documentation

class Alias(roles.DMLTableRole, AliasedReturnsRows):

Known subclasses: sqlalchemy.sql.expression.TableValuedAlias

Represents an table or selectable alias (AS).

Represents an alias, as typically applied to any table or sub-select within a SQL statement using the AS keyword (or without the keyword on certain databases such as Oracle).

This object is constructed from the _expression.alias module level function as well as the _expression.FromClause.alias method available on all _expression.FromClause subclasses.

See Also

_expression.FromClause.alias

Class Method	`_factory`	Return an `_expression.Alias` object.
Class Variable	`__visit_name__`	Undocumented
Class Variable	`inherit_cache`	Indicate if this `.HasCacheKey` instance should make use of the cache key generation scheme used by its immediate superclass.

Inherited from DMLTableRole:

Class Variable _role_name Undocumented

Inherited from FromClauseRole (via DMLTableRole):

Class Variable	`_is_subquery`	Undocumented
Property	`_hide_froms`	Undocumented

Inherited from ColumnsClauseRole (via DMLTableRole, FromClauseRole):

Property _select_iterable Undocumented

Inherited from AllowsLambdaRole (via DMLTableRole, FromClauseRole, ColumnsClauseRole):

Class Variable allows_lambda Undocumented

Inherited from UsesInspection (via DMLTableRole, FromClauseRole, ColumnsClauseRole):

Class Variable	`_post_inspect`	Undocumented
Class Variable	`uses_inspection`	Undocumented

Inherited from SQLRole (via DMLTableRole, FromClauseRole, ColumnsClauseRole, ColumnListRole):

Class Variable	`allows_lambda`	Undocumented
Class Variable	`uses_inspection`	Undocumented

Inherited from AllowsLambdaRole (via DMLTableRole, FromClauseRole, JoinTargetRole):

Class Variable allows_lambda Undocumented

Inherited from UsesInspection (via DMLTableRole, FromClauseRole, JoinTargetRole):

Class Variable	`_post_inspect`	Undocumented
Class Variable	`uses_inspection`	Undocumented

Inherited from SQLRole (via DMLTableRole, FromClauseRole, JoinTargetRole, StructuralRole):

Class Variable	`allows_lambda`	Undocumented
Class Variable	`uses_inspection`	Undocumented

Inherited from AliasedReturnsRows:

Method	`is_derived_from`	Return `True` if this `_expression.FromClause` is 'derived' from the given `FromClause`.
Class Method	`_construct`	Undocumented
Method	`_copy_internals`	Reassign internal elements to be clones of themselves.
Method	`_init`	Undocumented
Method	`_populate_column_collection`	Called on subclasses to establish the .c collection.
Method	`_refresh_for_new_column`	Given a column added to the .c collection of an underlying selectable, produce the local version of that column, assuming this selectable ultimately should proxy this column.
Class Variable	`_is_from_container`	Undocumented
Class Variable	`_supports_derived_columns`	Undocumented
Class Variable	`_traverse_internals`	Undocumented
Class Variable	`named_with_column`	Undocumented
Instance Variable	`_orig_name`	Undocumented
Instance Variable	`element`	Undocumented
Instance Variable	`name`	Undocumented
Property	`_from_objects`	Undocumented
Property	`bind`	Undocumented
Property	`description`	A brief description of this `_expression.FromClause`.
Property	`original`	Legacy for dialects that are referring to Alias.original.

Inherited from NoInit (via AliasedReturnsRows):

Method __init__ Undocumented

Inherited from FromClause (via AliasedReturnsRows):

Method	`alias`	Return an alias of this `_expression.FromClause`.
Method	`join`	Return a `_expression.Join` from this `_expression.FromClause` to another `FromClause`.
Method	`outerjoin`	No summary
Method	`select`	Return a SELECT of this `_expression.FromClause`.
Method	`table_valued`	Return a `_sql.TableValuedColumn` object for this `_expression.FromClause`.
Method	`tablesample`	Return a TABLESAMPLE alias of this `_expression.FromClause`.
Class Variable	`c`	Undocumented
Class Variable	`schema`	Define the 'schema' attribute for this `_expression.FromClause`.
Instance Variable	`foreign_keys`	Return the collection of `_schema.ForeignKey` marker objects which this FromClause references.
Instance Variable	`primary_key`	Return the iterable collection of `_schema.Column` objects which comprise the primary key of this `_selectable.FromClause`.
Method	`_anonymous_fromclause`	Undocumented
Method	`_generate_fromclause_column_proxies`	Undocumented
Method	`_init_collections`	Undocumented
Method	`_is_lexical_equivalent`	Return `True` if this `_expression.FromClause` and the other represent the same lexical identity.
Method	`_reset_column_collection`	Reset the attributes linked to the `FromClause.c` attribute.
Class Variable	`_hide_froms`	Undocumented
Class Variable	`_is_from_clause`	Undocumented
Class Variable	`_is_join`	Undocumented
Class Variable	`_select_iterable`	Undocumented
Class Variable	`_use_schema_map`	Undocumented
Class Variable	`is_selectable`	Undocumented
Instance Variable	`_columns`	Undocumented
Property	`_cols_populated`	Undocumented
Property	`columns`	A named-based collection of `_expression.ColumnElement` objects maintained by this `_expression.FromClause`.
Property	`entity_namespace`	Return a namespace used for name-based access in SQL expressions.
Property	`exported_columns`	A `_expression.ColumnCollection` that represents the "exported" columns of this `_expression.Selectable`.

Inherited from FromClauseRole (via AliasedReturnsRows, FromClause, AnonymizedFromClauseRole, StrictFromClauseRole):

Class Variable	`_is_subquery`	Undocumented
Class Variable	`_role_name`	Undocumented

Inherited from AllowsLambdaRole (via AliasedReturnsRows, FromClause, AnonymizedFromClauseRole, StrictFromClauseRole, FromClauseRole, ColumnsClauseRole):

Class Variable allows_lambda Undocumented

Inherited from UsesInspection (via AliasedReturnsRows, FromClause, AnonymizedFromClauseRole, StrictFromClauseRole, FromClauseRole, ColumnsClauseRole):

Class Variable	`_post_inspect`	Undocumented
Class Variable	`uses_inspection`	Undocumented

Inherited from SQLRole (via AliasedReturnsRows, FromClause, AnonymizedFromClauseRole, StrictFromClauseRole, FromClauseRole, ColumnsClauseRole, ColumnListRole):

Class Variable	`allows_lambda`	Undocumented
Class Variable	`uses_inspection`	Undocumented

Inherited from AllowsLambdaRole (via AliasedReturnsRows, FromClause, AnonymizedFromClauseRole, StrictFromClauseRole, FromClauseRole, JoinTargetRole):

Class Variable allows_lambda Undocumented

Inherited from UsesInspection (via AliasedReturnsRows, FromClause, AnonymizedFromClauseRole, StrictFromClauseRole, FromClauseRole, JoinTargetRole):

Class Variable	`_post_inspect`	Undocumented
Class Variable	`uses_inspection`	Undocumented

Inherited from SQLRole (via AliasedReturnsRows, FromClause, AnonymizedFromClauseRole, StrictFromClauseRole, FromClauseRole, JoinTargetRole, StructuralRole):

Class Variable	`allows_lambda`	Undocumented
Class Variable	`uses_inspection`	Undocumented

Inherited from Selectable (via AliasedReturnsRows, FromClause):

Method	`corresponding_column`	No summary
Method	`lateral`	Return a LATERAL alias of this `_expression.Selectable`.
Method	`replace_selectable`	Replace all occurrences of `_expression.FromClause` 'old' with the given `_expression.Alias` object, returning a copy of this `_expression.FromClause`.

Inherited from ReturnsRows (via AliasedReturnsRows, FromClause, Selectable):

Class Variable	`_is_lateral`	Undocumented
Class Variable	`_is_returns_rows`	Undocumented
Class Variable	`_is_select_statement`	Undocumented
Property	`_all_selected_columns`	A sequence of column expression objects that represents the "selected" columns of this `_expression.ReturnsRows`.
Property	`selectable`	Undocumented

Inherited from ReturnsRowsRole (via AliasedReturnsRows, FromClause, Selectable, ReturnsRows):

Class Variable _role_name Undocumented

Inherited from SQLRole (via AliasedReturnsRows, FromClause, Selectable, ReturnsRows, ReturnsRowsRole):

Class Variable	`allows_lambda`	Undocumented
Class Variable	`uses_inspection`	Undocumented

Inherited from ClauseElement (via AliasedReturnsRows, FromClause, Selectable, ReturnsRows):

Method	`compare`	Compare this `_expression.ClauseElement` to the given `_expression.ClauseElement`.
Method	`compile`	Compile this SQL expression.
Method	`params`	Return a copy with `_expression.bindparam` elements replaced.
Method	`self_group`	Apply a 'grouping' to this `_expression.ClauseElement`.
Method	`unique_params`	Return a copy with `_expression.bindparam` elements replaced.
Method	`__bool__`	Undocumented
Method	`__getstate__`	Undocumented
Method	`__invert__`	Undocumented
Method	`__repr__`	Undocumented
Method	`__str__`	Undocumented
Method	`_clone`	Create a shallow copy of this ClauseElement.
Method	`_cloned_set`	Return the set consisting all cloned ancestors of this ClauseElement.
Method	`_compile_w_cache`	Undocumented
Method	`_compiler`	Return a compiler appropriate for this ClauseElement, given a Dialect.
Method	`_execute_on_connection`	Undocumented
Method	`_negate`	Undocumented
Method	`_negate_in_binary`	a hook to allow the right side of a binary expression to respond to a negation of the binary expression.
Method	`_replace_params`	Undocumented
Method	`_set_propagate_attrs`	Undocumented
Method	`_ungroup`	Return this `_expression.ClauseElement` without any groupings.
Method	`_with_binary_element_type`	in the context of binary expression, convert the type of this object to the one given.
Class Variable	`_cache_key_traversal`	Undocumented
Class Variable	`_is_bind_parameter`	Undocumented
Class Variable	`_is_clause_list`	Undocumented
Class Variable	`_is_clone_of`	Undocumented
Class Variable	`_is_immutable`	Undocumented
Class Variable	`_is_lambda_element`	Undocumented
Class Variable	`_is_select_container`	Undocumented
Class Variable	`_is_singleton_constant`	Undocumented
Class Variable	`_is_text_clause`	Undocumented
Class Variable	`_is_textual`	Undocumented
Class Variable	`_order_by_label_element`	Undocumented
Class Variable	`is_clause_element`	Undocumented
Class Variable	`stringify_dialect`	Undocumented
Class Variable	`supports_execution`	Undocumented
Instance Variable	`_propagate_attrs`	like annotations, however these propagate outwards liberally as SQL constructs are built, and are set up at construction time.
Property	`_constructor`	return the 'constructor' for this ClauseElement.

Inherited from SQLRole (via AliasedReturnsRows, FromClause, Selectable, ReturnsRows, ClauseElement):

Class Variable	`allows_lambda`	Undocumented
Class Variable	`uses_inspection`	Undocumented

Inherited from SupportsWrappingAnnotations (via AliasedReturnsRows, FromClause, Selectable, ReturnsRows, ClauseElement):

Method	`_annotate`	return a copy of this ClauseElement with annotations updated by the given dictionary.
Method	`_deannotate`	return a copy of this `_expression.ClauseElement` with annotations removed.
Method	`_with_annotations`	return a copy of this ClauseElement with annotations replaced by the given dictionary.

Inherited from SupportsAnnotations (via AliasedReturnsRows, FromClause, Selectable, ReturnsRows, ClauseElement, SupportsWrappingAnnotations):

Property _annotations_cache_key Undocumented

Inherited from MemoizedHasCacheKey (via AliasedReturnsRows, FromClause, Selectable, ReturnsRows, ClauseElement):

Method _generate_cache_key return a cache key.

Inherited from HasCacheKey (via AliasedReturnsRows, FromClause, Selectable, ReturnsRows, ClauseElement, MemoizedHasCacheKey):

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.
Class Variable	`__slots__`	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 Traversible (via AliasedReturnsRows, FromClause, Selectable, ReturnsRows, ClauseElement):

Method	`get_children`	Return immediate child `.visitors.Traversible` elements of this `.visitors.Traversible`.
Method	`__class_getitem__`	Undocumented

@classmethod
def _factory(cls, selectable, name=None, flat=False):

overrides sqlalchemy.sql.expression.AliasedReturnsRows._factory

Return an _expression.Alias object.

An _expression.Alias represents any _expression.FromClause with an alternate name assigned within SQL, typically using the AS clause when generated, e.g. SELECT * FROM table AS aliasname.

Similar functionality is available via the _expression.FromClause.alias method available on all _expression.FromClause subclasses. In terms of a SELECT object as generated from the _expression.select function, the _expression.SelectBase.alias method returns an _expression.Alias or similar object which represents a named, parenthesized subquery.

When an _expression.Alias is created from a _schema.Table object, this has the effect of the table being rendered as tablename AS aliasname in a SELECT statement.

For _expression.select objects, the effect is that of creating a named subquery, i.e. (select ...) AS aliasname.

The name parameter is optional, and provides the name to use in the rendered SQL. If blank, an "anonymous" name will be deterministically generated at compile time. Deterministic means the name is guaranteed to be unique against other constructs used in the same statement, and will also be the same name for each successive compilation of the same statement object.

Parameters
selectable	any `_expression.FromClause` subclass, such as a table, select statement, etc.
name	string name to be assigned as the alias. If `None`, a name will be deterministically generated at compile time.
flat	Will be passed through to if the given selectable is an instance of `_expression.Join` - see `_expression.Join.alias` for details.

__visit_name__: str =

overrides sqlalchemy.sql.expression.FromClause.__visit_name__

overridden in sqlalchemy.sql.expression.TableValuedAlias

Undocumented

inherit_cache: bool =

overrides sqlalchemy.sql.traversals.HasCacheKey.inherit_cache

Indicate if this .HasCacheKey instance should make use of the cache key generation scheme used by its immediate superclass.

The attribute defaults to None, which indicates that a construct has not yet taken into account whether or not its appropriate for it to participate in caching; this is functionally equivalent to setting the value to False, except that a warning is also emitted.

This flag can be set to True on a particular class, if the SQL that corresponds to the object does not change based on attributes which are local to this class, and not its superclass.