class LambdaElement(elements.ClauseElement): (source)
Known subclasses: sqlalchemy.sql.lambdas.DeferredLambdaElement
, sqlalchemy.sql.lambdas.StatementLambdaElement
A SQL construct where the state is stored as an un-invoked lambda. The :class:`_sql.LambdaElement` is produced transparently whenever passing lambda expressions into SQL constructs, such as:: stmt = select(table).where(lambda: table.c.col == parameter) The :class:`_sql.LambdaElement` is the base of the :class:`_sql.StatementLambdaElement` which represents a full statement within a lambda. .. versionadded:: 1.4 .. seealso:: :ref:`engine_lambda_caching`
Method | __getattr__ |
Undocumented |
Method | __init__ |
Undocumented |
Method | __repr__ |
Undocumented |
Class Variable | __visit |
Undocumented |
Class Variable | parent |
Undocumented |
Instance Variable | closure |
Undocumented |
Instance Variable | fn |
Undocumented |
Instance Variable | opts |
Undocumented |
Instance Variable | role |
Undocumented |
Instance Variable | tracker |
Undocumented |
Method | _copy |
Reassign internal elements to be clones of themselves. |
Method | _gen |
return an optional cache key. |
Method | _invoke |
Undocumented |
Method | _param |
Undocumented |
Method | _retrieve |
Undocumented |
Method | _setup |
Undocumented |
Class Variable | _is |
Undocumented |
Class Variable | _transforms |
Undocumented |
Class Variable | _traverse |
Undocumented |
Instance Variable | _rec |
Undocumented |
Instance Variable | _resolved |
Undocumented |
Property | _from |
Undocumented |
Property | _is |
Undocumented |
Property | _resolved |
Undocumented |
Property | _select |
Undocumented |
Inherited from ClauseElement
:
Method | __bool__ |
Undocumented |
Method | __getstate__ |
Undocumented |
Method | __invert__ |
Undocumented |
Method | compare |
Compare this :class:`_expression.ClauseElement` to the given :class:`_expression.ClauseElement`. |
Method | get |
Return immediate child :class:`.visitors.HasTraverseInternals` elements of this :class:`.visitors.HasTraverseInternals`. |
Method | params |
Return a copy with :func:`_expression.bindparam` elements replaced. |
Method | self |
Apply a 'grouping' to this :class:`_expression.ClauseElement`. |
Method | unique |
Return a copy with :func:`_expression.bindparam` elements replaced. |
Class Variable | is |
Undocumented |
Class Variable | is |
Undocumented |
Class Variable | is |
Undocumented |
Class Variable | negation |
Undocumented |
Property | description |
Undocumented |
Property | entity |
Undocumented |
Method | _clone |
Create a shallow copy of this ClauseElement. |
Method | _cloned |
Return the set consisting all cloned ancestors of this ClauseElement. |
Method | _compile |
Undocumented |
Method | _execute |
Undocumented |
Method | _execute |
an additional hook for subclasses to provide a different implementation for connection.scalar() vs. connection.execute(). |
Method | _negate |
Undocumented |
Method | _negate |
a hook to allow the right side of a binary expression to respond to a negation of the binary expression. |
Method | _replace |
Undocumented |
Method | _set |
Undocumented |
Method | _ungroup |
Return this :class:`_expression.ClauseElement` without any groupings. |
Method | _with |
in the context of binary expression, convert the type of this object to the one given. |
Class Variable | _cache |
Undocumented |
Class Variable | _gen |
Undocumented |
Class Variable | _is |
Undocumented |
Class Variable | _is |
Undocumented |
Class Variable | _is |
Undocumented |
Class Variable | _is |
Undocumented |
Class Variable | _is |
Undocumented |
Class Variable | _is |
Undocumented |
Class Variable | _is |
Undocumented |
Class Variable | _is |
Undocumented |
Class Variable | _is |
Undocumented |
Class Variable | _is |
Undocumented |
Class Variable | _is |
Undocumented |
Class Variable | _is |
Undocumented |
Class Variable | _is |
Undocumented |
Class Variable | _is |
Undocumented |
Class Variable | _is |
Undocumented |
Class Variable | _is |
Undocumented |
Class Variable | _is |
Undocumented |
Instance Variable | _propagate |
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 | _order |
Undocumented |
Inherited from SupportsWrappingAnnotations
(via ClauseElement
):
Class Variable | __slots__ |
Undocumented |
Method | _annotate |
return a copy of this ClauseElement with annotations updated by the given dictionary. |
Method | _deannotate |
return a copy of this :class:`_expression.ClauseElement` with annotations removed. |
Method | _with |
return a copy of this ClauseElement with annotations replaced by the given dictionary. |
Inherited from SupportsAnnotations
(via ClauseElement
, SupportsWrappingAnnotations
):
Class Variable | proxy |
Undocumented |
Method | _gen |
Undocumented |
Property | _annotations |
Undocumented |
Inherited from MemoizedHasCacheKey
(via ClauseElement
, SupportsWrappingAnnotations
, SupportsAnnotations
):
Method | _generate |
return a cache key. |
Inherited from HasCacheKey
(via ClauseElement
, SupportsWrappingAnnotations
, SupportsAnnotations
, MemoizedHasCacheKey
):
Class Variable | inherit |
Indicate if this :class:`.HasCacheKey` instance should make use of the cache key generation scheme used by its immediate superclass. |
Class Method | _generate |
generate cache key dispatcher for a new class. |
Class Method | _generate |
Undocumented |
Class Variable | _generated |
Undocumented |
Class Variable | _hierarchy |
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 |
Undocumented |
Inherited from CompilerElement
(via ClauseElement
, SupportsWrappingAnnotations
, SupportsAnnotations
, MemoizedHasCacheKey
, HasCacheKey
, HasCopyInternals
, ExternallyTraversible
, HasTraverseInternals
):
Method | __str__ |
Undocumented |
Method | compile |
Compile this SQL expression. |
Class Variable | stringify |
Undocumented |
Class Variable | supports |
Undocumented |
Method | _compiler |
Return a compiler appropriate for this ClauseElement, given a Dialect. |
Inherited from Visitable
(via ClauseElement
, SupportsWrappingAnnotations
, SupportsAnnotations
, MemoizedHasCacheKey
, HasCacheKey
, HasCopyInternals
, ExternallyTraversible
, HasTraverseInternals
, CompilerElement
):
Method | __class |
Undocumented |
Method | __init |
Undocumented |
Class Method | _generate |
Undocumented |
Method | _compiler |
Undocumented |
Class Variable | _original |
Undocumented |
_LambdaType
, role: Type[ SQLRole]
, opts: Union[ Type[ LambdaOptions], LambdaOptions]
= LambdaOptions, apply_propagate_attrs: Optional[ ClauseElement]
= None):
(source)
¶
sqlalchemy.sql.lambdas.DeferredLambdaElement
, sqlalchemy.sql.lambdas.StatementLambdaElement
Undocumented
_CloneCallableType
= _clone, deferred_copy_internals: Optional[ _CloneCallableType]
= None, **kw: Any
):
(source)
¶
sqlalchemy.sql.lambdas.DeferredLambdaElement
Reassign internal elements to be clones of themselves. Called during a copy-and-traverse operation on newly shallow-copied elements to create a deep copy. The given clone function should be used, which may be applying additional transformations to the element (i.e. replacement traversal, cloned traversal, annotations).
return an optional cache key. The cache key is a tuple which can contain any series of objects that are hashable and also identifies this object uniquely within the presence of a larger SQL expression or statement, for the purposes of caching the resulting query. The cache key should be based on the SQL compiled structure that would ultimately be produced. That is, two structures that are composed in exactly the same way should produce the same cache key; any difference in the structures that would affect the SQL string or the type handlers should result in a different cache key. If a structure cannot produce a useful cache key, the NO_CACHE symbol should be added to the anon_map and the method should return None.
sqlalchemy.sql.lambdas.DeferredLambdaElement
, sqlalchemy.sql.lambdas.LinkedLambdaElement
Undocumented