sqlalchemy.sql.selectable.SelectBase

class documentation

class SelectBase(roles.SelectStatementRole, roles.DMLSelectRole, roles.CompoundElementRole, roles.InElementRole, HasCTE, Executable, SupportsCloneAnnotations, Selectable):

Known subclasses: sqlalchemy.sql.selectable.GenerativeSelect, sqlalchemy.sql.selectable.TextualSelect, sqlalchemy.orm.query.FromStatement, sqlalchemy.sql.selectable.SelectStatementGrouping

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Base class for SELECT statements.

This includes _expression.Select, _expression.CompoundSelect and _expression.TextualSelect.

Method	`_ensure_disambiguated_names`	Ensure that the names generated by this selectbase will be disambiguated in some way, if possible.
Method	`_generate_fromclause_column_proxies`	Undocumented
Method	`_implicit_subquery`	Undocumented
Method	`_refresh_for_new_column`	Undocumented
Method	`alias`	Return a named subquery against this `_expression.SelectBase`.
Method	`as_scalar`	Undocumented
Method	`exists`	Return an `_sql.Exists` representation of this selectable, which can be used as a column expression.
Method	`label`	Return a 'scalar' representation of this selectable, embedded as a subquery with a label.
Method	`lateral`	Return a LATERAL alias of this `_expression.Selectable`.
Method	`scalar_subquery`	Return a 'scalar' representation of this selectable, which can be used as a column expression.
Method	`select`	Undocumented
Method	`subquery`	Return a subquery of this `_expression.SelectBase`.
Class Variable	`_is_select_statement`	Undocumented
Class Variable	`is_select`	Undocumented
Property	`_all_selected_columns`	A sequence of expressions that correspond to what is rendered in the columns clause, including `_sql.TextClause` constructs.
Property	`_from_objects`	Undocumented
Property	`c`	Undocumented
Property	`columns`	Undocumented
Property	`exported_columns`	No summary
Property	`selected_columns`	A `_expression.ColumnCollection` representing the columns that this SELECT statement or similar construct returns in its result set.

Inherited from SelectStatementRole:

Class Variable _role_name Undocumented

Inherited from StatementRole (via SelectStatementRole):

Class Variable _propagate_attrs Undocumented

Inherited from SQLRole (via SelectStatementRole, StatementRole):

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

Inherited from SQLRole (via SelectStatementRole, ReturnsRowsRole):

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

Inherited from DMLSelectRole:

Class Variable _role_name Undocumented

Inherited from SQLRole (via DMLSelectRole):

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

Inherited from CompoundElementRole:

Class Variable _role_name Undocumented

Inherited from AllowsLambdaRole (via CompoundElementRole):

Class Variable allows_lambda Undocumented

Inherited from SQLRole (via CompoundElementRole):

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

Inherited from InElementRole:

Class Variable _role_name Undocumented

Inherited from SQLRole (via InElementRole):

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

Inherited from HasCTE:

Method	`add_cte`	Add a `_sql.CTE` to this statement object that will be independently rendered even if not referenced in the statement otherwise.
Method	`cte`	Return a new `_expression.CTE`, or Common Table Expression instance.
Class Variable	`_has_ctes_traverse_internals`	Undocumented
Class Variable	`_independent_ctes`	Undocumented

Inherited from ReturnsRowsRole (via HasCTE, HasCTERole):

Class Variable _role_name Undocumented

Inherited from SQLRole (via HasCTE, HasCTERole, ReturnsRowsRole):

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

Inherited from Executable:

Method	`_add_context_option`	Add a context option to this statement.
Method	`_set_compile_options`	Assign the compile options to a new value.
Method	`_update_compile_options`	update the _compile_options with new keys.
Method	`execute`	Compile and execute this `.Executable`.
Method	`execution_options`	Set non-SQL options for the statement which take effect during execution.
Method	`get_execution_options`	Get the non-SQL options which will take effect during execution.
Method	`options`	Apply options to this statement.
Method	`scalar`	Compile and execute this `.Executable`, returning the result's scalar representation.
Class Variable	`_bind`	Undocumented
Class Variable	`_executable_traverse_internals`	Undocumented
Class Variable	`_with_context_options`	Undocumented
Class Variable	`_with_options`	Undocumented
Class Variable	`is_delete`	Undocumented
Class Variable	`is_dml`	Undocumented
Class Variable	`is_insert`	Undocumented
Class Variable	`is_text`	Undocumented
Class Variable	`is_update`	Undocumented
Class Variable	`supports_execution`	Undocumented
Instance Variable	`_compile_options`	Undocumented
Instance Variable	`_execution_options`	Undocumented
Property	`_effective_plugin_target`	Undocumented
Property	`bind`	Returns the `_engine.Engine` or `_engine.Connection` to which this `.Executable` is bound, or None if none found.

Inherited from StatementRole (via Executable):

Class Variable	`_propagate_attrs`	Undocumented
Class Variable	`_role_name`	Undocumented

Inherited from SQLRole (via Executable, StatementRole):

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

Inherited from Generative (via Executable):

Method _generate Undocumented

Inherited from SupportsCloneAnnotations:

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.
Class Variable	`_clone_annotations_traverse_internals`	Undocumented

Inherited from SupportsAnnotations (via SupportsCloneAnnotations):

Property _annotations_cache_key Undocumented

Inherited from Selectable:

Method	`corresponding_column`	No summary
Method	`replace_selectable`	Replace all occurrences of `_expression.FromClause` 'old' with the given `_expression.Alias` object, returning a copy of this `_expression.FromClause`.
Class Variable	`__visit_name__`	Undocumented
Class Variable	`is_selectable`	Undocumented

Inherited from ReturnsRows (via Selectable):

Class Variable	`_is_from_clause`	Undocumented
Class Variable	`_is_lateral`	Undocumented
Class Variable	`_is_returns_rows`	Undocumented
Property	`selectable`	Undocumented

Inherited from ReturnsRowsRole (via Selectable, ReturnsRows):

Class Variable _role_name Undocumented

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

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

Inherited from ClauseElement (via 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_from_container`	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	`bind`	Undocumented
Class Variable	`description`	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.
Property	`entity_namespace`	Undocumented

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

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

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

Property _annotations_cache_key Undocumented

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

Method _generate_cache_key return a cache key.

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

Class Variable	`inherit_cache`	Indicate if this `.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.
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 HasCopyInternals (via Selectable, ReturnsRows, ClauseElement):

Method _copy_internals Reassign internal elements to be clones of themselves.

Inherited from Traversible (via Selectable, ReturnsRows, ClauseElement):

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

def _ensure_disambiguated_names(self):

overridden in sqlalchemy.sql.expression.CompoundSelect, sqlalchemy.sql.expression.Select, sqlalchemy.sql.selectable.TextualSelect, sqlalchemy.orm.query.FromStatement, sqlalchemy.sql.selectable.SelectStatementGrouping

Ensure that the names generated by this selectbase will be disambiguated in some way, if possible.

def _generate_fromclause_column_proxies(self, fromclause):

overridden in sqlalchemy.sql.expression.CompoundSelect, sqlalchemy.sql.expression.Select, sqlalchemy.sql.selectable.TextualSelect, sqlalchemy.sql.selectable.SelectStatementGrouping

Undocumented

@HasMemoized.memoized_attribute
def _implicit_subquery(self):

Undocumented

def _refresh_for_new_column(self, column):

overrides sqlalchemy.sql.expression.Selectable._refresh_for_new_column

overridden in sqlalchemy.sql.expression.CompoundSelect

Undocumented

def alias(self, name=None, flat=False):

Return a named subquery against this _expression.SelectBase.

For a _expression.SelectBase (as opposed to a _expression.FromClause), this returns a .Subquery object which behaves mostly the same as the _expression.Alias object that is used with a _expression.FromClause.

Changed in version 1.4: The _expression.SelectBase.alias method is now a synonym for the _expression.SelectBase.subquery method.

@util.deprecated('1.4', 'The :meth:`_expression.SelectBase.as_scalar` method is deprecated and will be removed in a future release. Please refer to :meth:`_expression.SelectBase.scalar_subquery`.')
def as_scalar(self):

Undocumented

def exists(self):

Return an _sql.Exists representation of this selectable, which can be used as a column expression.

The returned object is an instance of _sql.Exists.

See Also

_sql.exists

:ref:`tutorial_exists` - in the :term:`2.0 style` tutorial.

New in version 1.4.

def label(self, name):

Return a 'scalar' representation of this selectable, embedded as a subquery with a label.

See Also

_expression.SelectBase.as_scalar.

def lateral(self, name=None):

overrides sqlalchemy.sql.expression.Selectable.lateral

Return a LATERAL alias of this _expression.Selectable.

The return value is the _expression.Lateral construct also provided by the top-level _expression.lateral function.

New in version 1.1.

See Also

:ref:`lateral_selects` - overview of usage.

def scalar_subquery(self):

Return a 'scalar' representation of this selectable, which can be used as a column expression.

The returned object is an instance of _sql.ScalarSelect.

Typically, a select statement which has only one column in its columns clause is eligible to be used as a scalar expression. The scalar subquery can then be used in the WHERE clause or columns clause of an enclosing SELECT.

Note that the scalar subquery differentiates from the FROM-level subquery that can be produced using the _expression.SelectBase.subquery method.

See Also

:ref:`tutorial_scalar_subquery` - in the 2.0 tutorial

:ref:`scalar_selects` - in the 1.x tutorial

@util.deprecated('1.4', 'The :meth:`_expression.SelectBase.select` method is deprecated and will be removed in a future release; this method implicitly creates a subquery that should be explicit. Please call :meth:`_expression.SelectBase.subquery` first in order to create a subquery, which then can be selected.')
def select(self, *arg, **kw):

Undocumented

def subquery(self, name=None):

overrides sqlalchemy.sql.roles.SelectStatementRole.subquery

Return a subquery of this _expression.SelectBase.

A subquery is from a SQL perspective a parenthesized, named construct that can be placed in the FROM clause of another SELECT statement.

Given a SELECT statement such as:

stmt = select(table.c.id, table.c.name)

The above statement might look like:

SELECT table.id, table.name FROM table

The subquery form by itself renders the same way, however when embedded into the FROM clause of another SELECT statement, it becomes a named sub-element:

subq = stmt.subquery()
new_stmt = select(subq)

The above renders as:

SELECT anon_1.id, anon_1.name
FROM (SELECT table.id, table.name FROM table) AS anon_1

Historically, _expression.SelectBase.subquery is equivalent to calling the _expression.FromClause.alias method on a FROM object; however, as a _expression.SelectBase object is not directly FROM object, the _expression.SelectBase.subquery method provides clearer semantics.

New in version 1.4.

_is_select_statement: bool =

overrides sqlalchemy.sql.selectable.ReturnsRows._is_select_statement

Undocumented

is_select: bool =

overrides sqlalchemy.sql.base.Executable.is_select

overridden in sqlalchemy.sql.selectable.TextualSelect

Undocumented

@property
_all_selected_columns =

overrides sqlalchemy.sql.selectable.ReturnsRows._all_selected_columns

overridden in sqlalchemy.sql.expression.CompoundSelect, sqlalchemy.sql.expression.Select, sqlalchemy.sql.selectable.TextualSelect, sqlalchemy.sql.selectable.SelectStatementGrouping

A sequence of expressions that correspond to what is rendered in the columns clause, including _sql.TextClause constructs.

New in version 1.4.12.

See Also

_sql.SelectBase.exported_columns

@property
_from_objects =

overrides sqlalchemy.sql.expression.ClauseElement._from_objects

overridden in sqlalchemy.sql.selectable.SelectStatementGrouping

Undocumented

@property
@util.deprecated('1.4', 'The :attr:`_expression.SelectBase.c` and :attr:`_expression.SelectBase.columns` attributes are deprecated and will be removed in a future release; these attributes implicitly create a subquery that should be explicit. Please call :meth:`_expression.SelectBase.subquery` first in order to create a subquery, which then contains this attribute. To access the columns that this SELECT object SELECTs from, use the :attr:`_expression.SelectBase.selected_columns` attribute.')
c =

Undocumented

@property
columns =

Undocumented

@property
exported_columns =

overrides sqlalchemy.sql.selectable.ReturnsRows.exported_columns

A _expression.ColumnCollection that represents the "exported" columns of this _expression.Selectable, not including _sql.TextClause constructs.

The "exported" columns for a _expression.SelectBase object are synonymous with the _expression.SelectBase.selected_columns collection.

New in version 1.4.

See Also

_expression.Select.exported_columns

_expression.Selectable.exported_columns

_expression.FromClause.exported_columns

@property
selected_columns =

overridden in sqlalchemy.sql.expression.CompoundSelect, sqlalchemy.sql.expression.Select, sqlalchemy.sql.selectable.TextualSelect, sqlalchemy.sql.selectable.SelectStatementGrouping

A _expression.ColumnCollection representing the columns that this SELECT statement or similar construct returns in its result set.

This collection differs from the _expression.FromClause.columns collection of a _expression.FromClause in that the columns within this collection cannot be directly nested inside another SELECT statement; a subquery must be applied first which provides for the necessary parenthesization required by SQL.

Note

The _sql.SelectBase.selected_columns collection does not include expressions established in the columns clause using the _sql.text construct; these are silently omitted from the collection. To use plain textual column expressions inside of a _sql.Select construct, use the _sql.literal_column construct.

See Also

_sql.Select.selected_columns

New in version 1.4.