sqlalchemy.sql.expression.ClauseElement

class documentation

class ClauseElement(roles.SQLRole, SupportsWrappingAnnotations, MemoizedHasCacheKey, HasCopyInternals, Traversible):

Known subclasses: sqlalchemy.sql.dml.UpdateBase, sqlalchemy.sql.elements.ClauseList, sqlalchemy.sql.elements.TextClause, sqlalchemy.sql.expression.ColumnElement, sqlalchemy.sql.expression.LambdaElement, sqlalchemy.sql.selectable.ReturnsRows, sqlalchemy.databases.oracle._OuterJoinColumn, sqlalchemy.sql.ddl._DDLCompiles, sqlalchemy.sql.elements._IdentifiedClause, sqlalchemy.sql.elements.GroupedElement, sqlalchemy.sql.elements.TypeClause, sqlalchemy.sql.lambdas.NullLambdaStatement, sqlalchemy.sql.selectable.ForUpdateArg

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Base class for elements of a programmatically constructed SQL expression.

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	`__visit_name__`	Undocumented
Class Variable	`_cache_key_traversal`	Undocumented
Class Variable	`_from_objects`	Undocumented
Class Variable	`_is_bind_parameter`	Undocumented
Class Variable	`_is_clause_list`	Undocumented
Class Variable	`_is_clone_of`	Undocumented
Class Variable	`_is_from_clause`	Undocumented
Class Variable	`_is_from_container`	Undocumented
Class Variable	`_is_immutable`	Undocumented
Class Variable	`_is_lambda_element`	Undocumented
Class Variable	`_is_returns_rows`	Undocumented
Class Variable	`_is_select_container`	Undocumented
Class Variable	`_is_select_statement`	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	`is_selectable`	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:

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

Inherited from SupportsWrappingAnnotations:

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 SupportsWrappingAnnotations):

Property _annotations_cache_key Undocumented

Inherited from MemoizedHasCacheKey:

Method _generate_cache_key return a cache key.

Inherited from HasCacheKey (via 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:

Method _copy_internals Reassign internal elements to be clones of themselves.

Inherited from Traversible:

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

def compare(self, other, **kw):

overridden in sqlalchemy.sql.crud._multiparam_column

Compare this _expression.ClauseElement to the given _expression.ClauseElement.

Subclasses should override the default behavior, which is a straight identity comparison.

**kw are arguments consumed by subclass compare() methods and may be used to modify the criteria for comparison (see _expression.ColumnElement).

@util.preload_module('sqlalchemy.engine.default')
@util.preload_module('sqlalchemy.engine.url')
def compile(self, bind=None, dialect=None, **kw):

Compile this SQL expression.

The return value is a ~.Compiled object. Calling str() or unicode() on the returned value will yield a string representation of the result. The ~.Compiled object also can return a dictionary of bind parameter names and values using the params accessor.

See Also

:ref:`faq_sql_expression_string`

Parameters
bind	An `Engine` or `Connection` from which a `Compiled` will be acquired. This argument takes precedence over this `_expression.ClauseElement`'s bound engine, if any.
dialect	A `Dialect` instance from which a `Compiled` will be acquired. This argument takes precedence over the `bind` argument as well as this `_expression.ClauseElement` 's bound engine, if any.
**kw	Undocumented
column_keys	Used for INSERT and UPDATE statements, a list of column names which should be present in the VALUES clause of the compiled statement. If `None`, all columns from the target table object are rendered.
compile_kwargs	optional dictionary of additional parameters that will be passed through to the compiler within all "visit" methods. This allows any custom flag to be passed through to a custom compilation construct, for example. It is also used for the case of passing the `literal_binds` flag through: from sqlalchemy.sql import table, column, select t = table('t', column('x')) s = select(t).where(t.c.x == 5) print(s.compile(compile_kwargs={"literal_binds": True})) New in version 0.9.0.

def params(self, *optionaldict, **kwargs):

overridden in sqlalchemy.sql.dml.UpdateBase, sqlalchemy.sql.dml.UpdateBase

Return a copy with _expression.bindparam elements replaced.

Returns a copy of this ClauseElement with _expression.bindparam elements replaced with values taken from the given dictionary:

>>> clause = column('x') + bindparam('foo')
>>> print(clause.compile().params)
{'foo':None}
>>> print(clause.params({'foo':7}).compile().params)
{'foo':7}

def self_group(self, against=None):

overridden in sqlalchemy.sql.elements.ClauseList, sqlalchemy.sql.elements.TextClause, sqlalchemy.sql.expression.ColumnElement, sqlalchemy.sql.expression.CompoundSelect, sqlalchemy.sql.expression.Join, sqlalchemy.sql.expression.Select, sqlalchemy.sql.functions.FunctionElement, sqlalchemy.sql.elements.GroupedElement, sqlalchemy.sql.selectable.SelectStatementGrouping

Apply a 'grouping' to this _expression.ClauseElement.

This method is overridden by subclasses to return a "grouping" construct, i.e. parenthesis. In particular it's used by "binary" expressions to provide a grouping around themselves when placed into a larger expression, as well as by _expression.select constructs when placed into the FROM clause of another _expression.select. (Note that subqueries should be normally created using the _expression.Select.alias method, as many platforms require nested SELECT statements to be named).

As expressions are composed together, the application of self_group is automatic - end-user code should never need to use this method directly. Note that SQLAlchemy's clause constructs take operator precedence into account - so parenthesis might not be needed, for example, in an expression like x OR (y AND z) - AND takes precedence over OR.

The base self_group method of _expression.ClauseElement just returns self.

def unique_params(self, *optionaldict, **kwargs):

Return a copy with _expression.bindparam elements replaced.

Same functionality as _expression.ClauseElement.params, except adds unique=True to affected bind parameters so that multiple statements can be used.

def __bool__(self):

overridden in sqlalchemy.sql.elements.BinaryExpression

Undocumented

def __getstate__(self):

overridden in sqlalchemy.sql.elements.BindParameter, sqlalchemy.sql.elements.Grouping, sqlalchemy.sql.elements.Grouping, sqlalchemy.sql.selectable.FromGrouping, sqlalchemy.sql.selectable.FromGrouping

Undocumented

def __invert__(self):

Undocumented

def __repr__(self):

overridden in sqlalchemy.sql.ddl.DDL, sqlalchemy.sql.elements.BindParameter, sqlalchemy.sql.expression.LambdaElement, sqlalchemy.sql.schema.Column, sqlalchemy.sql.schema.Table

Undocumented

def __str__(self):

overridden in sqlalchemy.sql.expression.TableClause, sqlalchemy.sql.schema.Column

Undocumented

def _clone(self, **kw):

overrides sqlalchemy.sql.traversals.HasCopyInternals._clone

overridden in sqlalchemy.sql.elements.BindParameter, sqlalchemy.sql.elements.ColumnClause

Create a shallow copy of this ClauseElement.

This method may be used by a generative API. Its also used as part of the "deep" copy afforded by a traversal that combines the _copy_internals() method.

@HasMemoized.memoized_attribute
def _cloned_set(self):

Return the set consisting all cloned ancestors of this ClauseElement.

Includes this ClauseElement. This accessor tends to be used for FromClause objects to identify 'equivalent' FROM clauses, regardless of transformative operations.

def _compile_w_cache(self, dialect, compiled_cache=None, column_keys=None, for_executemany=False, schema_translate_map=None, **kw):

overridden in sqlalchemy.sql.ddl._DDLCompiles

Undocumented

def _compiler(self, dialect, **kw):

overridden in sqlalchemy.sql.ddl._DDLCompiles

Return a compiler appropriate for this ClauseElement, given a Dialect.

def _execute_on_connection(self, connection, multiparams, params, execution_options, _force=False):

overridden in sqlalchemy.sql.ddl.DDLElement, sqlalchemy.sql.expression.StatementLambdaElement, sqlalchemy.sql.expression.Subquery, sqlalchemy.sql.functions.FunctionElement, sqlalchemy.sql.lambdas.NullLambdaStatement

Undocumented

def _negate(self):

overridden in sqlalchemy.sql.expression.ColumnElement, sqlalchemy.sql.elements.BooleanClauseList

Undocumented

def _negate_in_binary(self, negated_op, original_op):

overridden in sqlalchemy.sql.elements.BindParameter

a hook to allow the right side of a binary expression to respond to a negation of the binary expression.

Used for the special case of expanding bind parameter with IN.

def _replace_params(self, unique, optionaldict, kwargs):

Undocumented

def _set_propagate_attrs(self, values):

Undocumented

def _ungroup(self):

overridden in sqlalchemy.sql.elements.GroupedElement

Return this _expression.ClauseElement without any groupings.

def _with_binary_element_type(self, type_):

overridden in sqlalchemy.sql.elements.BindParameter, sqlalchemy.sql.elements.Grouping, sqlalchemy.sql.elements.Grouping

in the context of binary expression, convert the type of this object to the one given.

applies only to _expression.ColumnElement classes.

__visit_name__: str =

overridden in sqlalchemy.sql.ddl.AddConstraint, sqlalchemy.sql.ddl.CreateColumn, sqlalchemy.sql.ddl.CreateIndex, sqlalchemy.sql.ddl.CreateSchema, sqlalchemy.sql.ddl.CreateSequence, sqlalchemy.sql.ddl.CreateTable, sqlalchemy.sql.ddl.DDL, sqlalchemy.sql.ddl.DropConstraint, sqlalchemy.sql.ddl.DropIndex, sqlalchemy.sql.ddl.DropSchema, sqlalchemy.sql.ddl.DropSequence, sqlalchemy.sql.ddl.DropTable, sqlalchemy.sql.dml.UpdateBase, sqlalchemy.sql.dml.UpdateBase, sqlalchemy.sql.elements.ClauseList, sqlalchemy.sql.elements.TextClause, sqlalchemy.sql.expression.ColumnElement, sqlalchemy.sql.expression.LambdaElement, sqlalchemy.sql.expression.Selectable, sqlalchemy.databases.oracle._OuterJoinColumn, sqlalchemy.dialects.postgresql.CreateEnumType, sqlalchemy.dialects.postgresql.DropEnumType, sqlalchemy.sql.ddl._DropView, sqlalchemy.sql.ddl.DropColumnComment, sqlalchemy.sql.ddl.DropTableComment, sqlalchemy.sql.ddl.SetColumnComment, sqlalchemy.sql.ddl.SetTableComment, sqlalchemy.sql.elements._IdentifiedClause, sqlalchemy.sql.elements.GroupedElement, sqlalchemy.sql.elements.TypeClause, sqlalchemy.sql.lambdas.NullLambdaStatement

Undocumented

_cache_key_traversal =

overridden in sqlalchemy.sql.expression.Select, sqlalchemy.orm.query.FromStatement

Undocumented

_from_objects: list =

overridden in sqlalchemy.dialects.postgresql.aggregate_order_by, sqlalchemy.sql.elements.BinaryExpression, sqlalchemy.sql.elements.Case, sqlalchemy.sql.elements.Cast, sqlalchemy.sql.elements.ClauseList, sqlalchemy.sql.elements.ColumnClause, sqlalchemy.sql.elements.Extract, sqlalchemy.sql.elements.FunctionFilter, sqlalchemy.sql.elements.Label, sqlalchemy.sql.elements.Over, sqlalchemy.sql.elements.TypeCoerce, sqlalchemy.sql.elements.UnaryExpression, sqlalchemy.sql.elements.WithinGroup, sqlalchemy.sql.expression.AliasedReturnsRows, sqlalchemy.sql.expression.Join, sqlalchemy.sql.expression.LambdaElement, sqlalchemy.sql.expression.TableClause, sqlalchemy.sql.expression.Values, sqlalchemy.sql.functions.FunctionElement, sqlalchemy.sql.selectable.SelectBase, sqlalchemy.sql.elements._label_reference, sqlalchemy.sql.elements.Grouping, sqlalchemy.sql.elements.Grouping, sqlalchemy.sql.elements.TableValuedColumn, sqlalchemy.sql.selectable.FromGrouping, sqlalchemy.sql.selectable.FromGrouping, sqlalchemy.sql.selectable.SelectStatementGrouping

Undocumented

_is_bind_parameter: bool =

overridden in sqlalchemy.sql.elements.BindParameter

Undocumented

_is_clause_list: bool =

overridden in sqlalchemy.sql.elements.ClauseList

Undocumented

_is_clone_of =

Undocumented

_is_from_clause: bool =

overridden in sqlalchemy.sql.selectable.ReturnsRows

Undocumented

_is_from_container: bool =

overridden in sqlalchemy.sql.expression.AliasedReturnsRows, sqlalchemy.sql.expression.CompoundSelect, sqlalchemy.sql.selectable.ScalarSelect, sqlalchemy.sql.selectable.ScalarSelect

Undocumented

_is_immutable: bool =

Undocumented

_is_lambda_element: bool =

overridden in sqlalchemy.sql.expression.LambdaElement, sqlalchemy.sql.lambdas.NullLambdaStatement

Undocumented

_is_returns_rows: bool =

overridden in sqlalchemy.sql.selectable.ReturnsRows

Undocumented

_is_select_container: bool =

overridden in sqlalchemy.sql.selectable.SelectStatementGrouping, sqlalchemy.sql.selectable.SelectStatementGrouping

Undocumented

_is_select_statement: bool =

overridden in sqlalchemy.sql.selectable.ReturnsRows

Undocumented

_is_singleton_constant: bool =

Undocumented

_is_text_clause: bool =

overridden in sqlalchemy.sql.elements.TextClause

Undocumented

_is_textual: bool =

overridden in sqlalchemy.sql.elements.TextClause, sqlalchemy.sql.selectable.TextualSelect

Undocumented

_order_by_label_element =

overridden in sqlalchemy.sql.elements.Label, sqlalchemy.sql.elements.UnaryExpression

Undocumented

bind =

overridden in sqlalchemy.sql.ddl.DDLElement, sqlalchemy.sql.dml.UpdateBase, sqlalchemy.sql.dml.UpdateBase, sqlalchemy.sql.expression.AliasedReturnsRows, sqlalchemy.sql.expression.CompoundSelect, sqlalchemy.sql.expression.Join, sqlalchemy.sql.expression.Select, sqlalchemy.sql.schema.Table

Undocumented

description =

overridden in sqlalchemy.sql.expression.FromClause, sqlalchemy.sql.elements.NamedColumn

Undocumented

is_clause_element: bool =

Undocumented

is_selectable: bool =

overridden in sqlalchemy.sql.expression.Selectable

Undocumented

stringify_dialect: str =

overridden in sqlalchemy.dialects.postgresql.aggregate_order_by, sqlalchemy.dialects.postgresql.array, sqlalchemy.dialects.postgresql.array, sqlalchemy.databases.mssql.TryCast, sqlalchemy.sql.ddl._CreateDropBase

Undocumented

supports_execution: bool =

Undocumented

_propagate_attrs =

overridden in sqlalchemy.sql.elements.BinaryExpression, sqlalchemy.sql.elements.UnaryExpression, sqlalchemy.sql.lambdas.LinkedLambdaElement, sqlalchemy.sql.lambdas.NullLambdaStatement

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.

This is for the purposes for creating a new object of this type. Usually, its just the element's __class__. However, the "Annotated" version of the object overrides to return the class of its proxied element.

@property
entity_namespace =

overridden in sqlalchemy.sql.elements.ColumnClause, sqlalchemy.sql.expression.FromClause

Undocumented