SQLAlchemy 1.1 Documentation

__eq__(other)¶

inherited from the __eq__() method of ColumnOperators

Implement the == operator.

In a column context, produces the clause a = b. If the target is None, produces a IS NULL.

__le__(other)¶

inherited from the __le__() method of ColumnOperators

Implement the <= operator.

In a column context, produces the clause a <= b.

__lt__(other)¶

inherited from the __lt__() method of ColumnOperators

Implement the < operator.

In a column context, produces the clause a < b.

__ne__(other)¶

inherited from the __ne__() method of ColumnOperators

Implement the != operator.

In a column context, produces the clause a != b. If the target is None, produces a IS NOT NULL.

adapt_to_entity(adapt_to_entity)¶: inherited from the adapt_to_entity() method of PropComparator

Return a copy of this PropComparator which will use the given AliasedInsp to produce corresponding expressions.

adapter¶: inherited from the adapter attribute of PropComparator

Produce a callable that adapts column expressions to suit an aliased version of this comparator.

all_()¶: inherited from the all_() method of ColumnOperators

Produce a all_() clause against the parent object.

버전 1.1에 추가.

any(criterion=None, **kwargs)¶

inherited from the any() method of PropComparator

Return true if this collection contains any member that meets the given criterion.

The usual implementation of any() is RelationshipProperty.Comparator.any().

매개 변수:	criterion¶ – an optional ClauseElement formulated against the member class’ table or attributes. **kwargs¶ – key/value pairs corresponding to member class attribute names which will be compared via equality to the corresponding values.

any_()¶: inherited from the any_() method of ColumnOperators

Produce a any_() clause against the parent object.

버전 1.1에 추가.

asc()¶: inherited from the asc() method of ColumnOperators

Produce a asc() clause against the parent object.

between(cleft, cright, symmetric=False)¶: inherited from the between() method of ColumnOperators

Produce a between() clause against the parent object, given the lower and upper range.

collate(collation)¶: inherited from the collate() method of ColumnOperators

Produce a collate() clause against the parent object, given the collation string.

concat(other)¶

inherited from the concat() method of ColumnOperators

Implement the ‘concat’ operator.

In a column context, produces the clause a || b, or uses the concat() operator on MySQL.

contains(other, **kwargs)¶

inherited from the contains() method of ColumnOperators

Implement the ‘contains’ operator.

In a column context, produces the clause LIKE '%<other>%'

desc()¶: inherited from the desc() method of ColumnOperators

Produce a desc() clause against the parent object.

distinct()¶: inherited from the distinct() method of ColumnOperators

Produce a distinct() clause against the parent object.

endswith(other, **kwargs)¶

inherited from the endswith() method of ColumnOperators

Implement the ‘endswith’ operator.

In a column context, produces the clause LIKE '%<other>'

has(criterion=None, **kwargs)¶

inherited from the has() method of PropComparator

Return true if this element references a member which meets the given criterion.

The usual implementation of has() is RelationshipProperty.Comparator.has().

매개 변수:	criterion¶ – an optional ClauseElement formulated against the member class’ table or attributes. **kwargs¶ – key/value pairs corresponding to member class attribute names which will be compared via equality to the corresponding values.

ilike(other, escape=None)¶

inherited from the ilike() method of ColumnOperators

Implement the ilike operator.

In a column context, produces the clause a ILIKE other.

E.g.:

select([sometable]).where(sometable.c.column.ilike("%foobar%"))

매개 변수:	other¶ – expression to be compared escape¶ – optional escape character, renders the `ESCAPE` keyword, e.g.: somecolumn.ilike("foo/%bar", escape="/")

in_(other)¶

inherited from the in_() method of ColumnOperators

Implement the in operator.

In a column context, produces the clause a IN other. “other” may be a tuple/list of column expressions, or a select() construct.

is_(other)¶

inherited from the is_() method of ColumnOperators

Implement the IS operator.

Normally, IS is generated automatically when comparing to a value of None, which resolves to NULL. However, explicit usage of IS may be desirable if comparing to boolean values on certain platforms.

버전 0.7.9에 추가.

isnot(other)¶

inherited from the isnot() method of ColumnOperators

Implement the IS NOT operator.

Normally, IS NOT is generated automatically when comparing to a value of None, which resolves to NULL. However, explicit usage of IS NOT may be desirable if comparing to boolean values on certain platforms.

버전 0.7.9에 추가.

like(other, escape=None)¶

inherited from the like() method of ColumnOperators

Implement the like operator.

In a column context, produces the clause a LIKE other.

E.g.:

select([sometable]).where(sometable.c.column.like("%foobar%"))

매개 변수:	other¶ – expression to be compared escape¶ – optional escape character, renders the `ESCAPE` keyword, e.g.: somecolumn.like("foo/%bar", escape="/")

match(other, **kwargs)¶

inherited from the match() method of ColumnOperators

Implements a database-specific ‘match’ operator.

match() attempts to resolve to a MATCH-like function or operator provided by the backend. Examples include:

Postgresql - renders x @@ to_tsquery(y)
MySQL - renders MATCH (x) AGAINST (y IN BOOLEAN MODE)
Oracle - renders CONTAINS(x, y)
other backends may provide special implementations.
Backends without any special implementation will emit the operator as “MATCH”. This is compatible with SQlite, for example.

notilike(other, escape=None)¶

inherited from the notilike() method of ColumnOperators

implement the NOT ILIKE operator.

This is equivalent to using negation with ColumnOperators.ilike(), i.e. ~x.ilike(y).

버전 0.8에 추가.

notin_(other)¶

inherited from the notin_() method of ColumnOperators

implement the NOT IN operator.

This is equivalent to using negation with ColumnOperators.in_(), i.e. ~x.in_(y).

버전 0.8에 추가.

notlike(other, escape=None)¶

inherited from the notlike() method of ColumnOperators

implement the NOT LIKE operator.

This is equivalent to using negation with ColumnOperators.like(), i.e. ~x.like(y).

버전 0.8에 추가.

nullsfirst()¶: inherited from the nullsfirst() method of ColumnOperators

Produce a nullsfirst() clause against the parent object.

nullslast()¶: inherited from the nullslast() method of ColumnOperators

Produce a nullslast() clause against the parent object.

of_type(class_)¶

inherited from the of_type() method of PropComparator

Redefine this object in terms of a polymorphic subclass.

Returns a new PropComparator from which further criterion can be evaluated.

e.g.:

query.join(Company.employees.of_type(Engineer)).\
   filter(Engineer.name=='foo')

매개 변수:	class_¶ – a class or mapper indicating that criterion will be against this specific subclass.

op(opstring, precedence=0, is_comparison=False)¶

inherited from the op() method of Operators

produce a generic operator function.

e.g.:

somecolumn.op("*")(5)

produces:

somecolumn * 5

This function can also be used to make bitwise operators explicit. For example:

somecolumn.op('&')(0xff)

is a bitwise AND of the value in somecolumn.

매개 변수:

operator¶ – a string which will be output as the infix operator between this element and the expression passed to the generated function.
precedence¶ –
precedence to apply to the operator, when parenthesizing expressions. A lower number will cause the expression to be parenthesized when applied against another operator with higher precedence. The default value of 0 is lower than all operators except for the comma (,) and AS operators. A value of 100 will be higher or equal to all operators, and -100 will be lower than or equal to all operators.

버전 0.8에 추가: - added the ‘precedence’ argument.
is_comparison¶ –
if True, the operator will be considered as a “comparison” operator, that is which evaluates to a boolean true/false value, like ==, >, etc. This flag should be set so that ORM relationships can establish that the operator is a comparison operator when used in a custom join condition.

버전 0.9.2에 추가: - added the Operators.op.is_comparison flag.

startswith(other, **kwargs)¶

inherited from the startswith() method of ColumnOperators

Implement the startwith operator.

In a column context, produces the clause LIKE '<other>%'

ColumnProperty.__init__(*columns, **kwargs)¶

Construct a new ColumnProperty object.

This constructor is mirrored as a public API function; see column_property() for a full usage and argument description.

ColumnProperty.cascade_iterator(type_, state, visited_instances=None, halt_on=None)¶

inherited from the cascade_iterator() method of MapperProperty

Iterate through instances related to the given instance for a particular ‘cascade’, starting with this MapperProperty.

Return an iterator3-tuples (instance, mapper, state).

Note that the ‘cascade’ collection on this MapperProperty is checked first for the given type before cascade_iterator is called.

This method typically only applies to RelationshipProperty.

ColumnProperty.class_attribute¶

inherited from the class_attribute attribute of MapperProperty

Return the class-bound descriptor corresponding to this MapperProperty.

This is basically a getattr() call:

return getattr(self.parent.class_, self.key)

I.e. if this MapperProperty were named addresses, and the class to which it is mapped is User, this sequence is possible:

>>> from sqlalchemy import inspect
>>> mapper = inspect(User)
>>> addresses_property = mapper.attrs.addresses
>>> addresses_property.class_attribute is User.addresses
True
>>> User.addresses.property is addresses_property
True

ColumnProperty.expression¶: Return the primary column or expression for this ColumnProperty.

ColumnProperty.extension_type = symbol('NOT_EXTENSION')¶

ColumnProperty.init()¶: inherited from the init() method of MapperProperty

Called after all mappers are created to assemble relationships between mappers and perform other post-mapper-creation initialization steps.

ColumnProperty.set_parent(parent, init)¶

inherited from the set_parent() method of MapperProperty

Set the parent mapper that references this MapperProperty.

This method is overridden by some subclasses to perform extra setup when the mapper is first known.

class sqlalchemy.orm.properties.ComparableProperty(comparator_factory, descriptor=None, doc=None, info=None)¶

Bases: sqlalchemy.orm.descriptor_props.DescriptorProperty

Instruments a Python property for use in query expressions.

__init__(comparator_factory, descriptor=None, doc=None, info=None)¶

Construct a new ComparableProperty object.

This constructor is mirrored as a public API function; see comparable_property() for a full usage and argument description.

class sqlalchemy.orm.descriptor_props.CompositeProperty(class_, *attrs, **kwargs)¶

Bases: sqlalchemy.orm.descriptor_props.DescriptorProperty

Defines a “composite” mapped attribute, representing a collection of columns as one attribute.

CompositeProperty is constructed using the composite() function.

Composite Column Types

class Comparator(prop, parentmapper, adapt_to_entity=None)¶

Bases: sqlalchemy.orm.interfaces.PropComparator

Produce boolean, comparison, and other operators for CompositeProperty attributes.

See the example in Redefining Comparison Operations for Composites for an overview of usage , as well as the documentation for PropComparator.

See also:

PropComparator

Mapper.all_orm_descriptors

CompositeProperty.__init__(class_, *attrs, **kwargs)¶

Construct a new CompositeProperty object.

This constructor is mirrored as a public API function; see composite() for a full usage and argument description.

CompositeProperty.do_init()¶: Initialization which occurs after the CompositeProperty has been associated with its parent mapper.

CompositeProperty.get_history(state, dict_, passive=symbol('PASSIVE_OFF'))¶: Provided for userland code that uses attributes.get_history().

class sqlalchemy.orm.attributes.Event(attribute_impl, op)¶

A token propagated throughout the course of a chain of attribute events.

Serves as an indicator of the source of the event and also provides a means of controlling propagation across a chain of attribute operations.

The Event object is sent as the initiator argument when dealing with the AttributeEvents.append(), AttributeEvents.set(), and AttributeEvents.remove() events.

The Event object is currently interpreted by the backref event handlers, and is used to control the propagation of operations across two mutually-dependent attributes.

버전 0.9.0에 추가.

변수:	impl – The `AttributeImpl` which is the current event initiator. op – The symbol `OP_APPEND`, `OP_REMOVE` or `OP_REPLACE`, indicating the source operation.

class sqlalchemy.orm.identity.IdentityMap¶

check_modified()¶: return True if any InstanceStates present have been marked as ‘modified’.

class sqlalchemy.orm.base.InspectionAttr¶

A base class applied to all ORM objects that can be returned by the inspect() function.

The attributes defined here allow the usage of simple boolean checks to test basic facts about the object returned.

While the boolean checks here are basically the same as using the Python isinstance() function, the flags here can be used without the need to import all of these classes, and also such that the SQLAlchemy class system can change while leaving the flags here intact for forwards-compatibility.

extension_type = symbol('NOT_EXTENSION')¶: The extension type, if any. Defaults to interfaces.NOT_EXTENSION

버전 0.8.0에 추가.

더 보기

HYBRID_METHOD

HYBRID_PROPERTY

ASSOCIATION_PROXY

is_aliased_class = False¶: True if this object is an instance of AliasedClass.

is_attribute = False¶

True if this object is a Python descriptor.

This can refer to one of many types. Usually a QueryableAttribute which handles attributes events on behalf of a MapperProperty. But can also be an extension type such as AssociationProxy or hybrid_property. The InspectionAttr.extension_type will refer to a constant identifying the specific subtype.

is_clause_element = False¶: True if this object is an instance of ClauseElement.

is_instance = False¶: True if this object is an instance of InstanceState.

is_mapper = False¶: True if this object is an instance of Mapper.

is_property = False¶: True if this object is an instance of MapperProperty.

is_selectable = False¶: Return True if this object is an instance of Selectable.

class sqlalchemy.orm.base.InspectionAttrInfo¶

Bases: sqlalchemy.orm.base.InspectionAttr

Adds the .info attribute to InspectionAttr.

The rationale for InspectionAttr vs. InspectionAttrInfo is that the former is compatible as a mixin for classes that specify __slots__; this is essentially an implementation artifact.

info¶

Info dictionary associated with the object, allowing user-defined data to be associated with this InspectionAttr.

The dictionary is generated when first accessed. Alternatively, it can be specified as a constructor argument to the column_property(), relationship(), or composite() functions.

버전 0.8에 추가: Added support for .info to all MapperProperty subclasses.

버전 1.0.0으로 변경: MapperProperty.info is also available on extension types via the InspectionAttrInfo.info attribute, so that it can apply to a wider variety of ORM and extension constructs.

QueryableAttribute.info

SchemaItem.info

class sqlalchemy.orm.state.InstanceState(obj, manager)¶

Bases: sqlalchemy.orm.base.InspectionAttr

tracks state information at the instance level.

The InstanceState is a key object used by the SQLAlchemy ORM in order to track the state of an object; it is created the moment an object is instantiated, typically as a result of instrumentation which SQLAlchemy applies to the __init__() method of the class.

InstanceState is also a semi-public object, available for runtime inspection as to the state of a mapped instance, including information such as its current status within a particular Session and details about data on individual attributes. The public API in order to acquire a InstanceState object is to use the inspect() system:

>>> from sqlalchemy import inspect
>>> insp = inspect(some_mapped_object)

Runtime Inspection API

attrs¶

Return a namespace representing each attribute on the mapped object, including its current value and history.

The returned object is an instance of AttributeState. This object allows inspection of the current data within an attribute as well as attribute history since the last flush.

callables = ()¶

A namespace where a per-state loader callable can be associated.

In SQLAlchemy 1.0, this is only used for lazy loaders / deferred loaders that were set up via query option.

Previously, callables was used also to indicate expired attributes by storing a link to the InstanceState itself in this dictionary. This role is now handled by the expired_attributes set.

deleted¶

Return true if the object is deleted.

An object that is in the deleted state is guaranteed to not be within the Session.identity_map of its parent Session; however if the session’s transaction is rolled back, the object will be restored to the persistent state and the identity map.

주석

The InstanceState.deleted attribute refers to a specific state of the object that occurs between the “persistent” and “detached” states; once the object is detached, the InstanceState.deleted attribute no longer returns True; in order to detect that a state was deleted, regardless of whether or not the object is associated with a Session, use the InstanceState.was_deleted accessor.

Quickie Intro to Object States

detached¶: Return true if the object is detached.

더 보기

Quickie Intro to Object States

dict¶

Return the instance dict used by the object.

Under normal circumstances, this is always synonymous with the __dict__ attribute of the mapped object, unless an alternative instrumentation system has been configured.

In the case that the actual object has been garbage collected, this accessor returns a blank dictionary.

expired_attributes = None¶

The set of keys which are ‘expired’ to be loaded by the manager’s deferred scalar loader, assuming no pending changes.

see also the unmodified collection which is intersected against this set when a refresh operation occurs.

has_identity¶

Return True if this object has an identity key.

This should always have the same value as the expression state.persistent or state.detached.

identity¶

Return the mapped identity of the mapped object. This is the primary key identity as persisted by the ORM which can always be passed directly to Query.get().

Returns None if the object has no primary key identity.

주석

An object which is transient or pending does not have a mapped identity until it is flushed, even if its attributes include primary key values.

identity_key¶

Return the identity key for the mapped object.

This is the key used to locate the object within the Session.identity_map mapping. It contains the identity as returned by identity within it.

mapper¶: Return the Mapper used for this mapepd object.

object¶: Return the mapped object represented by this InstanceState.

pending¶: Return true if the object is pending.

더 보기

Quickie Intro to Object States

persistent¶

Return true if the object is persistent.

An object that is in the persistent state is guaranteed to be within the Session.identity_map of its parent Session.

버전 1.1으로 변경: The InstanceState.persistent accessor no longer returns True for an object that was “deleted” within a flush; use the InstanceState.deleted accessor to detect this state. This allows the “persistent” state to guarantee membership in the identity map.

Quickie Intro to Object States

session¶

Return the owning Session for this instance, or None if none available.

Note that the result here can in some cases be different from that of obj in session; an object that’s been deleted will report as not in session, however if the transaction is still in progress, this attribute will still refer to that session. Only when the transaction is completed does the object become fully detached under normal circumstances.

transient¶: Return true if the object is transient.

더 보기

Quickie Intro to Object States

unloaded¶

Return the set of keys which do not have a loaded value.

This includes expired attributes and any other attribute that was never populated or modified.

unmodified¶: Return the set of keys which have no uncommitted changes

unmodified_intersection(keys)¶: Return self.unmodified.intersection(keys).

was_deleted¶

Return True if this object is or was previously in the “deleted” state and has not been reverted to persistent.

This flag returns True once the object was deleted in flush. When the object is expunged from the session either explicitly or via transaction commit and enters the “detached” state, this flag will continue to report True.

버전 1.1에 추가: - added a local method form of orm.util.was_deleted().

InstanceState.deleted - refers to the “deleted” state

orm.util.was_deleted() - standalone function

Quickie Intro to Object States

class sqlalchemy.orm.attributes.InstrumentedAttribute(class_, key, impl=None, comparator=None, parententity=None, of_type=None)¶

Bases: sqlalchemy.orm.attributes.QueryableAttribute

Class bound instrumented attribute which adds basic descriptor methods.

See QueryableAttribute for a description of most features.

__delete__(instance)¶

__get__(instance, owner)¶

__set__(instance, value)¶

sqlalchemy.orm.interfaces.MANYTOONE = symbol('MANYTOONE')¶

Indicates the many-to-one direction for a relationship().

This symbol is typically used by the internals but may be exposed within certain API features.

sqlalchemy.orm.interfaces.MANYTOMANY = symbol('MANYTOMANY')¶

Indicates the many-to-many direction for a relationship().

This symbol is typically used by the internals but may be exposed within certain API features.

class sqlalchemy.orm.interfaces.MapperProperty¶

Bases: sqlalchemy.orm.base._MappedAttribute, sqlalchemy.orm.base.InspectionAttr, sqlalchemy.util.langhelpers.MemoizedSlots

Represent a particular class attribute mapped by Mapper.

The most common occurrences of MapperProperty are the mapped Column, which is represented in a mapping as an instance of ColumnProperty, and a reference to another class produced by relationship(), represented in the mapping as an instance of RelationshipProperty.

info¶

Info dictionary associated with the object, allowing user-defined data to be associated with this InspectionAttr.

The dictionary is generated when first accessed. Alternatively, it can be specified as a constructor argument to the column_property(), relationship(), or composite() functions.

버전 0.8에 추가: Added support for .info to all MapperProperty subclasses.

버전 1.0.0으로 변경: InspectionAttr.info moved from MapperProperty so that it can apply to a wider variety of ORM and extension constructs.

QueryableAttribute.info

SchemaItem.info

cascade = frozenset([])¶

The set of ‘cascade’ attribute names.

This collection is checked before the ‘cascade_iterator’ method is called.

The collection typically only applies to a RelationshipProperty.

cascade_iterator(type_, state, visited_instances=None, halt_on=None)¶

Iterate through instances related to the given instance for a particular ‘cascade’, starting with this MapperProperty.

Return an iterator3-tuples (instance, mapper, state).

Note that the ‘cascade’ collection on this MapperProperty is checked first for the given type before cascade_iterator is called.

This method typically only applies to RelationshipProperty.

class_attribute¶

Return the class-bound descriptor corresponding to this MapperProperty.

This is basically a getattr() call:

return getattr(self.parent.class_, self.key)

I.e. if this MapperProperty were named addresses, and the class to which it is mapped is User, this sequence is possible:

>>> from sqlalchemy import inspect
>>> mapper = inspect(User)
>>> addresses_property = mapper.attrs.addresses
>>> addresses_property.class_attribute is User.addresses
True
>>> User.addresses.property is addresses_property
True

create_row_processor(context, path, mapper, result, adapter, populators)¶: Produce row processing functions and append to the given set of populators lists.

do_init()¶

Perform subclass-specific initialization post-mapper-creation steps.

This is a template method called by the MapperProperty object’s init() method.

init()¶: Called after all mappers are created to assemble relationships between mappers and perform other post-mapper-creation initialization steps.

instrument_class(mapper)¶

Hook called by the Mapper to the property to initiate instrumentation of the class attribute managed by this MapperProperty.

The MapperProperty here will typically call out to the attributes module to set up an InstrumentedAttribute.

This step is the first of two steps to set up an InstrumentedAttribute, and is called early in the mapper setup process.

The second step is typically the init_class_attribute step, called from StrategizedProperty via the post_instrument_class() hook. This step assigns additional state to the InstrumentedAttribute (specifically the “impl”) which has been determined after the MapperProperty has determined what kind of persistence management it needs to do (e.g. scalar, object, collection, etc).

is_property = True¶: Part of the InspectionAttr interface; states this object is a mapper property.

merge(session, source_state, source_dict, dest_state, dest_dict, load, _recursive, _resolve_conflict_map)¶: Merge the attribute represented by this MapperProperty from source to destination object.

post_instrument_class(mapper)¶

Perform instrumentation adjustments that need to occur after init() has completed.

The given Mapper is the Mapper invoking the operation, which may not be the same Mapper as self.parent in an inheritance scenario; however, Mapper will always at least be a sub-mapper of self.parent.

This method is typically used by StrategizedProperty, which delegates it to LoaderStrategy.init_class_attribute() to perform final setup on the class-bound InstrumentedAttribute.

set_parent(parent, init)¶

Set the parent mapper that references this MapperProperty.

This method is overridden by some subclasses to perform extra setup when the mapper is first known.

setup(context, entity, path, adapter, **kwargs)¶

Called by Query for the purposes of constructing a SQL statement.

Each MapperProperty associated with the target mapper processes the statement referenced by the query context, adding columns and/or criterion as appropriate.

sqlalchemy.orm.interfaces.NOT_EXTENSION = symbol('NOT_EXTENSION')¶

Symbol indicating an InspectionAttr that’s not part of sqlalchemy.ext.

Is assigned to the InspectionAttr.extension_type attibute.

sqlalchemy.orm.interfaces.ONETOMANY = symbol('ONETOMANY')¶

Indicates the one-to-many direction for a relationship().

This symbol is typically used by the internals but may be exposed within certain API features.

class sqlalchemy.orm.interfaces.PropComparator(prop, parentmapper, adapt_to_entity=None)¶

Bases: sqlalchemy.sql.operators.ColumnOperators

Defines SQL operators for MapperProperty objects.

SQLAlchemy allows for operators to be redefined at both the Core and ORM level. PropComparator is the base class of operator redefinition for ORM-level operations, including those of ColumnProperty, RelationshipProperty, and CompositeProperty.

주석

With the advent of Hybrid properties introduced in SQLAlchemy 0.7, as well as Core-level operator redefinition in SQLAlchemy 0.8, the use case for user-defined PropComparator instances is extremely rare. See Hybrid Attributes as well as Redefining and Creating New Operators.

User-defined subclasses of PropComparator may be created. The built-in Python comparison and math operator methods, such as operators.ColumnOperators.__eq__(), operators.ColumnOperators.__lt__(), and operators.ColumnOperators.__add__(), can be overridden to provide new operator behavior. The custom PropComparator is passed to the MapperProperty instance via the comparator_factory argument. In each case, the appropriate subclass of PropComparator should be used:

# definition of custom PropComparator subclasses

from sqlalchemy.orm.properties import \
                        ColumnProperty,\
                        CompositeProperty,\
                        RelationshipProperty

class MyColumnComparator(ColumnProperty.Comparator):
    def __eq__(self, other):
        return self.__clause_element__() == other

class MyRelationshipComparator(RelationshipProperty.Comparator):
    def any(self, expression):
        "define the 'any' operation"
        # ...

class MyCompositeComparator(CompositeProperty.Comparator):
    def __gt__(self, other):
        "redefine the 'greater than' operation"

        return sql.and_(*[a>b for a, b in
                          zip(self.__clause_element__().clauses,
                              other.__composite_values__())])


# application of custom PropComparator subclasses

from sqlalchemy.orm import column_property, relationship, composite
from sqlalchemy import Column, String

class SomeMappedClass(Base):
    some_column = column_property(Column("some_column", String),
                        comparator_factory=MyColumnComparator)

    some_relationship = relationship(SomeOtherClass,
                        comparator_factory=MyRelationshipComparator)

    some_composite = composite(
            Column("a", String), Column("b", String),
            comparator_factory=MyCompositeComparator
        )

Note that for column-level operator redefinition, it’s usually simpler to define the operators at the Core level, using the TypeEngine.comparator_factory attribute. See Redefining and Creating New Operators for more detail.

See also:

ColumnProperty.Comparator

RelationshipProperty.Comparator

CompositeProperty.Comparator

__eq__(other)¶

inherited from the __eq__() method of ColumnOperators

Implement the == operator.

In a column context, produces the clause a = b. If the target is None, produces a IS NULL.

__le__(other)¶

inherited from the __le__() method of ColumnOperators

Implement the <= operator.

In a column context, produces the clause a <= b.

__lt__(other)¶

inherited from the __lt__() method of ColumnOperators

Implement the < operator.

In a column context, produces the clause a < b.

__ne__(other)¶

inherited from the __ne__() method of ColumnOperators

Implement the != operator.

In a column context, produces the clause a != b. If the target is None, produces a IS NOT NULL.

adapt_to_entity(adapt_to_entity)¶: Return a copy of this PropComparator which will use the given AliasedInsp to produce corresponding expressions.

adapter¶: Produce a callable that adapts column expressions to suit an aliased version of this comparator.

all_()¶: inherited from the all_() method of ColumnOperators

Produce a all_() clause against the parent object.

버전 1.1에 추가.

any(criterion=None, **kwargs)¶

Return true if this collection contains any member that meets the given criterion.

The usual implementation of any() is RelationshipProperty.Comparator.any().

매개 변수:	criterion¶ – an optional ClauseElement formulated against the member class’ table or attributes. **kwargs¶ – key/value pairs corresponding to member class attribute names which will be compared via equality to the corresponding values.

any_()¶: inherited from the any_() method of ColumnOperators

Produce a any_() clause against the parent object.

버전 1.1에 추가.

asc()¶: inherited from the asc() method of ColumnOperators

Produce a asc() clause against the parent object.

between(cleft, cright, symmetric=False)¶: inherited from the between() method of ColumnOperators

Produce a between() clause against the parent object, given the lower and upper range.

collate(collation)¶: inherited from the collate() method of ColumnOperators

Produce a collate() clause against the parent object, given the collation string.

concat(other)¶

inherited from the concat() method of ColumnOperators

Implement the ‘concat’ operator.

In a column context, produces the clause a || b, or uses the concat() operator on MySQL.

contains(other, **kwargs)¶

inherited from the contains() method of ColumnOperators

Implement the ‘contains’ operator.

In a column context, produces the clause LIKE '%<other>%'

desc()¶: inherited from the desc() method of ColumnOperators

Produce a desc() clause against the parent object.

distinct()¶: inherited from the distinct() method of ColumnOperators

Produce a distinct() clause against the parent object.

endswith(other, **kwargs)¶

inherited from the endswith() method of ColumnOperators

Implement the ‘endswith’ operator.

In a column context, produces the clause LIKE '%<other>'

has(criterion=None, **kwargs)¶

Return true if this element references a member which meets the given criterion.

The usual implementation of has() is RelationshipProperty.Comparator.has().

매개 변수:	criterion¶ – an optional ClauseElement formulated against the member class’ table or attributes. **kwargs¶ – key/value pairs corresponding to member class attribute names which will be compared via equality to the corresponding values.

ilike(other, escape=None)¶

inherited from the ilike() method of ColumnOperators

Implement the ilike operator.

In a column context, produces the clause a ILIKE other.

E.g.:

select([sometable]).where(sometable.c.column.ilike("%foobar%"))

매개 변수:	other¶ – expression to be compared escape¶ – optional escape character, renders the `ESCAPE` keyword, e.g.: somecolumn.ilike("foo/%bar", escape="/")

in_(other)¶

inherited from the in_() method of ColumnOperators

Implement the in operator.

In a column context, produces the clause a IN other. “other” may be a tuple/list of column expressions, or a select() construct.

is_(other)¶

inherited from the is_() method of ColumnOperators

Implement the IS operator.

Normally, IS is generated automatically when comparing to a value of None, which resolves to NULL. However, explicit usage of IS may be desirable if comparing to boolean values on certain platforms.

버전 0.7.9에 추가.

isnot(other)¶

inherited from the isnot() method of ColumnOperators

Implement the IS NOT operator.

Normally, IS NOT is generated automatically when comparing to a value of None, which resolves to NULL. However, explicit usage of IS NOT may be desirable if comparing to boolean values on certain platforms.

버전 0.7.9에 추가.

like(other, escape=None)¶

inherited from the like() method of ColumnOperators

Implement the like operator.

In a column context, produces the clause a LIKE other.

E.g.:

select([sometable]).where(sometable.c.column.like("%foobar%"))

매개 변수:	other¶ – expression to be compared escape¶ – optional escape character, renders the `ESCAPE` keyword, e.g.: somecolumn.like("foo/%bar", escape="/")

match(other, **kwargs)¶

inherited from the match() method of ColumnOperators

Implements a database-specific ‘match’ operator.

match() attempts to resolve to a MATCH-like function or operator provided by the backend. Examples include:

Postgresql - renders x @@ to_tsquery(y)
MySQL - renders MATCH (x) AGAINST (y IN BOOLEAN MODE)
Oracle - renders CONTAINS(x, y)
other backends may provide special implementations.
Backends without any special implementation will emit the operator as “MATCH”. This is compatible with SQlite, for example.

notilike(other, escape=None)¶

inherited from the notilike() method of ColumnOperators

implement the NOT ILIKE operator.

This is equivalent to using negation with ColumnOperators.ilike(), i.e. ~x.ilike(y).

버전 0.8에 추가.

notin_(other)¶

inherited from the notin_() method of ColumnOperators

implement the NOT IN operator.

This is equivalent to using negation with ColumnOperators.in_(), i.e. ~x.in_(y).

버전 0.8에 추가.

notlike(other, escape=None)¶

inherited from the notlike() method of ColumnOperators

implement the NOT LIKE operator.

This is equivalent to using negation with ColumnOperators.like(), i.e. ~x.like(y).

버전 0.8에 추가.

nullsfirst()¶: inherited from the nullsfirst() method of ColumnOperators

Produce a nullsfirst() clause against the parent object.

nullslast()¶: inherited from the nullslast() method of ColumnOperators

Produce a nullslast() clause against the parent object.

of_type(class_)¶

Redefine this object in terms of a polymorphic subclass.

Returns a new PropComparator from which further criterion can be evaluated.

e.g.:

query.join(Company.employees.of_type(Engineer)).\
   filter(Engineer.name=='foo')

매개 변수:	class_¶ – a class or mapper indicating that criterion will be against this specific subclass.

op(opstring, precedence=0, is_comparison=False)¶

inherited from the op() method of Operators

produce a generic operator function.

e.g.:

somecolumn.op("*")(5)

produces:

somecolumn * 5

This function can also be used to make bitwise operators explicit. For example:

somecolumn.op('&')(0xff)

is a bitwise AND of the value in somecolumn.

매개 변수:

operator¶ – a string which will be output as the infix operator between this element and the expression passed to the generated function.
precedence¶ –
precedence to apply to the operator, when parenthesizing expressions. A lower number will cause the expression to be parenthesized when applied against another operator with higher precedence. The default value of 0 is lower than all operators except for the comma (,) and AS operators. A value of 100 will be higher or equal to all operators, and -100 will be lower than or equal to all operators.

버전 0.8에 추가: - added the ‘precedence’ argument.
is_comparison¶ –
if True, the operator will be considered as a “comparison” operator, that is which evaluates to a boolean true/false value, like ==, >, etc. This flag should be set so that ORM relationships can establish that the operator is a comparison operator when used in a custom join condition.

버전 0.9.2에 추가: - added the Operators.op.is_comparison flag.

Relationship Configuration

operate(op, *other, **kwargs)¶

inherited from the operate() method of Operators

Operate on an argument.

This is the lowest level of operation, raises NotImplementedError by default.

Overriding this on a subclass can allow common behavior to be applied to all operations. For example, overriding ColumnOperators to apply func.lower() to the left and right side:

class MyComparator(ColumnOperators):
    def operate(self, op, other):
        return op(func.lower(self), func.lower(other))

매개 변수:	op¶ – Operator callable. other¶ – the ‘other’ side of the operation. Will be a single scalar for most operations. *kwargs¶ – modifiers. These may be passed by special operators such as `ColumnOperators.contains()`.

reverse_operate(op, other, **kwargs)¶

inherited from the reverse_operate() method of Operators

Reverse operate on an argument.

Usage is the same as operate().

startswith(other, **kwargs)¶

inherited from the startswith() method of ColumnOperators

Implement the startwith operator.

In a column context, produces the clause LIKE '<other>%'

class sqlalchemy.orm.properties.RelationshipProperty(argument, secondary=None, primaryjoin=None, secondaryjoin=None, foreign_keys=None, uselist=None, order_by=False, backref=None, back_populates=None, post_update=False, cascade=False, extension=None, viewonly=False, lazy=True, collection_class=None, passive_deletes=False, passive_updates=True, remote_side=None, enable_typechecks=True, join_depth=None, comparator_factory=None, single_parent=False, innerjoin=False, distinct_target_key=None, doc=None, active_history=False, cascade_backrefs=True, load_on_pending=False, bake_queries=True, strategy_class=None, _local_remote_pairs=None, query_class=None, info=None)¶

Bases: sqlalchemy.orm.interfaces.StrategizedProperty

Describes an object property that holds a single item or list of items that correspond to a related database table.

Public constructor is the orm.relationship() function.

See also:

class Comparator(prop, parentmapper, adapt_to_entity=None, of_type=None)¶

Bases: sqlalchemy.orm.interfaces.PropComparator

Produce boolean, comparison, and other operators for RelationshipProperty attributes.

See the documentation for PropComparator for a brief overview of ORM level operator definition.

See also:

PropComparator

ColumnProperty.Comparator

__eq__(other)¶

Implement the == operator.

In a many-to-one context, such as:

MyClass.some_prop == <some object>

this will typically produce a clause such as:

mytable.related_id == <some id>

Where <some id> is the primary key of the given object.

The == operator provides partial functionality for non- many-to-one comparisons:

Comparisons against collections are not supported. Use contains().
Compared to a scalar one-to-many, will produce a clause that compares the target columns in the parent to the given target.
Compared to a scalar many-to-many, an alias of the association table will be rendered as well, forming a natural join that is part of the main body of the query. This will not work for queries that go beyond simple AND conjunctions of comparisons, such as those which use OR. Use explicit joins, outerjoins, or has() for more comprehensive non-many-to-one scalar membership tests.
Comparisons against None given in a one-to-many or many-to-many context produce a NOT EXISTS clause.

__init__(prop, parentmapper, adapt_to_entity=None, of_type=None)¶: Construction of RelationshipProperty.Comparator is internal to the ORM’s attribute mechanics.

__le__(other)¶

inherited from the __le__() method of ColumnOperators

Implement the <= operator.

In a column context, produces the clause a <= b.

__lt__(other)¶

inherited from the __lt__() method of ColumnOperators

Implement the < operator.

In a column context, produces the clause a < b.

__ne__(other)¶

Implement the != operator.

In a many-to-one context, such as:

MyClass.some_prop != <some object>

This will typically produce a clause such as:

mytable.related_id != <some id>

Where <some id> is the primary key of the given object.

The != operator provides partial functionality for non- many-to-one comparisons:

Comparisons against collections are not supported. Use contains() in conjunction with not_().
Compared to a scalar one-to-many, will produce a clause that compares the target columns in the parent to the given target.
Compared to a scalar many-to-many, an alias of the association table will be rendered as well, forming a natural join that is part of the main body of the query. This will not work for queries that go beyond simple AND conjunctions of comparisons, such as those which use OR. Use explicit joins, outerjoins, or has() in conjunction with not_() for more comprehensive non-many-to-one scalar membership tests.
Comparisons against None given in a one-to-many or many-to-many context produce an EXISTS clause.

adapter¶: inherited from the adapter attribute of PropComparator

Produce a callable that adapts column expressions to suit an aliased version of this comparator.

all_()¶: inherited from the all_() method of ColumnOperators

Produce a all_() clause against the parent object.

버전 1.1에 추가.

any(criterion=None, **kwargs)¶

Produce an expression that tests a collection against particular criterion, using EXISTS.

An expression like:

session.query(MyClass).filter(
    MyClass.somereference.any(SomeRelated.x==2)
)

Will produce a query like:

SELECT * FROM my_table WHERE
EXISTS (SELECT 1 FROM related WHERE related.my_id=my_table.id
AND related.x=2)

Because any() uses a correlated subquery, its performance is not nearly as good when compared against large target tables as that of using a join.

any() is particularly useful for testing for empty collections:

session.query(MyClass).filter(
    ~MyClass.somereference.any()
)

will produce:

SELECT * FROM my_table WHERE
NOT EXISTS (SELECT 1 FROM related WHERE
related.my_id=my_table.id)

any() is only valid for collections, i.e. a relationship() that has uselist=True. For scalar references, use has().

any_()¶: inherited from the any_() method of ColumnOperators

Produce a any_() clause against the parent object.

버전 1.1에 추가.

asc()¶: inherited from the asc() method of ColumnOperators

Produce a asc() clause against the parent object.

between(cleft, cright, symmetric=False)¶: inherited from the between() method of ColumnOperators

Produce a between() clause against the parent object, given the lower and upper range.

collate(collation)¶: inherited from the collate() method of ColumnOperators

Produce a collate() clause against the parent object, given the collation string.

concat(other)¶

inherited from the concat() method of ColumnOperators

Implement the ‘concat’ operator.

In a column context, produces the clause a || b, or uses the concat() operator on MySQL.

contains(other, **kwargs)¶

Return a simple expression that tests a collection for containment of a particular item.

contains() is only valid for a collection, i.e. a relationship() that implements one-to-many or many-to-many with uselist=True.

When used in a simple one-to-many context, an expression like:

MyClass.contains(other)

Produces a clause like:

mytable.id == <some id>

Where <some id> is the value of the foreign key attribute on other which refers to the primary key of its parent object. From this it follows that contains() is very useful when used with simple one-to-many operations.

For many-to-many operations, the behavior of contains() has more caveats. The association table will be rendered in the statement, producing an “implicit” join, that is, includes multiple tables in the FROM clause which are equated in the WHERE clause:

query(MyClass).filter(MyClass.contains(other))

Produces a query like:

SELECT * FROM my_table, my_association_table AS
my_association_table_1 WHERE
my_table.id = my_association_table_1.parent_id
AND my_association_table_1.child_id = <some id>

Where <some id> would be the primary key of other. From the above, it is clear that contains() will not work with many-to-many collections when used in queries that move beyond simple AND conjunctions, such as multiple contains() expressions joined by OR. In such cases subqueries or explicit “outer joins” will need to be used instead. See any() for a less-performant alternative using EXISTS, or refer to Query.outerjoin() as well as Querying with Joins for more details on constructing outer joins.

desc()¶: inherited from the desc() method of ColumnOperators

Produce a desc() clause against the parent object.

distinct()¶: inherited from the distinct() method of ColumnOperators

Produce a distinct() clause against the parent object.

endswith(other, **kwargs)¶

inherited from the endswith() method of ColumnOperators

Implement the ‘endswith’ operator.

In a column context, produces the clause LIKE '%<other>'

has(criterion=None, **kwargs)¶

Produce an expression that tests a scalar reference against particular criterion, using EXISTS.

An expression like:

session.query(MyClass).filter(
    MyClass.somereference.has(SomeRelated.x==2)
)

Will produce a query like:

SELECT * FROM my_table WHERE
EXISTS (SELECT 1 FROM related WHERE
related.id==my_table.related_id AND related.x=2)

Because has() uses a correlated subquery, its performance is not nearly as good when compared against large target tables as that of using a join.

has() is only valid for scalar references, i.e. a relationship() that has uselist=False. For collection references, use any().

ilike(other, escape=None)¶

inherited from the ilike() method of ColumnOperators

Implement the ilike operator.

In a column context, produces the clause a ILIKE other.

E.g.:

select([sometable]).where(sometable.c.column.ilike("%foobar%"))

매개 변수:	other¶ – expression to be compared escape¶ – optional escape character, renders the `ESCAPE` keyword, e.g.: somecolumn.ilike("foo/%bar", escape="/")

in_(other)¶: Produce an IN clause - this is not implemented for relationship()-based attributes at this time.

is_(other)¶

inherited from the is_() method of ColumnOperators

Implement the IS operator.

Normally, IS is generated automatically when comparing to a value of None, which resolves to NULL. However, explicit usage of IS may be desirable if comparing to boolean values on certain platforms.

버전 0.7.9에 추가.

isnot(other)¶

inherited from the isnot() method of ColumnOperators

Implement the IS NOT operator.

Normally, IS NOT is generated automatically when comparing to a value of None, which resolves to NULL. However, explicit usage of IS NOT may be desirable if comparing to boolean values on certain platforms.

버전 0.7.9에 추가.

like(other, escape=None)¶

inherited from the like() method of ColumnOperators

Implement the like operator.

In a column context, produces the clause a LIKE other.

E.g.:

select([sometable]).where(sometable.c.column.like("%foobar%"))

매개 변수:	other¶ – expression to be compared escape¶ – optional escape character, renders the `ESCAPE` keyword, e.g.: somecolumn.like("foo/%bar", escape="/")

mapper¶

The target Mapper referred to by this RelationshipProperty.Comparator.

This is the “target” or “remote” side of the relationship().

match(other, **kwargs)¶

inherited from the match() method of ColumnOperators

Implements a database-specific ‘match’ operator.

match() attempts to resolve to a MATCH-like function or operator provided by the backend. Examples include:

Postgresql - renders x @@ to_tsquery(y)
MySQL - renders MATCH (x) AGAINST (y IN BOOLEAN MODE)
Oracle - renders CONTAINS(x, y)
other backends may provide special implementations.
Backends without any special implementation will emit the operator as “MATCH”. This is compatible with SQlite, for example.

notilike(other, escape=None)¶

inherited from the notilike() method of ColumnOperators

implement the NOT ILIKE operator.

This is equivalent to using negation with ColumnOperators.ilike(), i.e. ~x.ilike(y).

버전 0.8에 추가.

notin_(other)¶

inherited from the notin_() method of ColumnOperators

implement the NOT IN operator.

This is equivalent to using negation with ColumnOperators.in_(), i.e. ~x.in_(y).

버전 0.8에 추가.

notlike(other, escape=None)¶

inherited from the notlike() method of ColumnOperators

implement the NOT LIKE operator.

This is equivalent to using negation with ColumnOperators.like(), i.e. ~x.like(y).

버전 0.8에 추가.

nullsfirst()¶: inherited from the nullsfirst() method of ColumnOperators

Produce a nullsfirst() clause against the parent object.

nullslast()¶: inherited from the nullslast() method of ColumnOperators

Produce a nullslast() clause against the parent object.

of_type(cls)¶

Produce a construct that represents a particular ‘subtype’ of attribute for the parent class.

Currently this is usable in conjunction with Query.join() and Query.outerjoin().

op(opstring, precedence=0, is_comparison=False)¶

inherited from the op() method of Operators

produce a generic operator function.

e.g.:

somecolumn.op("*")(5)

produces:

somecolumn * 5

This function can also be used to make bitwise operators explicit. For example:

somecolumn.op('&')(0xff)

is a bitwise AND of the value in somecolumn.

매개 변수:

operator¶ – a string which will be output as the infix operator between this element and the expression passed to the generated function.
precedence¶ –
precedence to apply to the operator, when parenthesizing expressions. A lower number will cause the expression to be parenthesized when applied against another operator with higher precedence. The default value of 0 is lower than all operators except for the comma (,) and AS operators. A value of 100 will be higher or equal to all operators, and -100 will be lower than or equal to all operators.

버전 0.8에 추가: - added the ‘precedence’ argument.
is_comparison¶ –
if True, the operator will be considered as a “comparison” operator, that is which evaluates to a boolean true/false value, like ==, >, etc. This flag should be set so that ORM relationships can establish that the operator is a comparison operator when used in a custom join condition.

버전 0.9.2에 추가: - added the Operators.op.is_comparison flag.

Mapper.all_orm_descriptors

operate(op, *other, **kwargs)¶

inherited from the operate() method of Operators

Operate on an argument.

This is the lowest level of operation, raises NotImplementedError by default.

Overriding this on a subclass can allow common behavior to be applied to all operations. For example, overriding ColumnOperators to apply func.lower() to the left and right side:

class MyComparator(ColumnOperators):
    def operate(self, op, other):
        return op(func.lower(self), func.lower(other))

매개 변수:	op¶ – Operator callable. other¶ – the ‘other’ side of the operation. Will be a single scalar for most operations. *kwargs¶ – modifiers. These may be passed by special operators such as `ColumnOperators.contains()`.

reverse_operate(op, other, **kwargs)¶

inherited from the reverse_operate() method of Operators

Reverse operate on an argument.

Usage is the same as operate().

startswith(other, **kwargs)¶

inherited from the startswith() method of ColumnOperators

Implement the startwith operator.

In a column context, produces the clause LIKE '<other>%'

RelationshipProperty.__init__(argument, secondary=None, primaryjoin=None, secondaryjoin=None, foreign_keys=None, uselist=None, order_by=False, backref=None, back_populates=None, post_update=False, cascade=False, extension=None, viewonly=False, lazy=True, collection_class=None, passive_deletes=False, passive_updates=True, remote_side=None, enable_typechecks=True, join_depth=None, comparator_factory=None, single_parent=False, innerjoin=False, distinct_target_key=None, doc=None, active_history=False, cascade_backrefs=True, load_on_pending=False, bake_queries=True, strategy_class=None, _local_remote_pairs=None, query_class=None, info=None)¶

Construct a new RelationshipProperty object.

This constructor is mirrored as a public API function; see relationship() for a full usage and argument description.

RelationshipProperty.cascade¶: Return the current cascade setting for this RelationshipProperty.

RelationshipProperty.class_attribute¶

inherited from the class_attribute attribute of MapperProperty

Return the class-bound descriptor corresponding to this MapperProperty.

This is basically a getattr() call:

return getattr(self.parent.class_, self.key)

I.e. if this MapperProperty were named addresses, and the class to which it is mapped is User, this sequence is possible:

>>> from sqlalchemy import inspect
>>> mapper = inspect(User)
>>> addresses_property = mapper.attrs.addresses
>>> addresses_property.class_attribute is User.addresses
True
>>> User.addresses.property is addresses_property
True

RelationshipProperty.extension_type = symbol('NOT_EXTENSION')¶

RelationshipProperty.init()¶: inherited from the init() method of MapperProperty

Called after all mappers are created to assemble relationships between mappers and perform other post-mapper-creation initialization steps.

RelationshipProperty.mapper¶

Return the targeted Mapper for this RelationshipProperty.

This is a lazy-initializing static attribute.

RelationshipProperty.set_parent(parent, init)¶

inherited from the set_parent() method of MapperProperty

Set the parent mapper that references this MapperProperty.

This method is overridden by some subclasses to perform extra setup when the mapper is first known.

RelationshipProperty.table¶: Return the selectable linked to this RelationshipProperty object’s target Mapper.

버전 0.7 폐지: Use .target

class sqlalchemy.orm.descriptor_props.SynonymProperty(name, map_column=None, descriptor=None, comparator_factory=None, doc=None, info=None)¶

Bases: sqlalchemy.orm.descriptor_props.DescriptorProperty

__init__(name, map_column=None, descriptor=None, comparator_factory=None, doc=None, info=None)¶

Construct a new SynonymProperty object.

This constructor is mirrored as a public API function; see synonym() for a full usage and argument description.

cascade_iterator(type_, state, visited_instances=None, halt_on=None)¶

inherited from the cascade_iterator() method of MapperProperty

Iterate through instances related to the given instance for a particular ‘cascade’, starting with this MapperProperty.

Return an iterator3-tuples (instance, mapper, state).

Note that the ‘cascade’ collection on this MapperProperty is checked first for the given type before cascade_iterator is called.

This method typically only applies to RelationshipProperty.

class_attribute¶

inherited from the class_attribute attribute of MapperProperty

Return the class-bound descriptor corresponding to this MapperProperty.

This is basically a getattr() call:

return getattr(self.parent.class_, self.key)

I.e. if this MapperProperty were named addresses, and the class to which it is mapped is User, this sequence is possible:

>>> from sqlalchemy import inspect
>>> mapper = inspect(User)
>>> addresses_property = mapper.attrs.addresses
>>> addresses_property.class_attribute is User.addresses
True
>>> User.addresses.property is addresses_property
True

create_row_processor(context, path, mapper, result, adapter, populators)¶: inherited from the create_row_processor() method of MapperProperty

Produce row processing functions and append to the given set of populators lists.

do_init()¶

inherited from the do_init() method of MapperProperty

Perform subclass-specific initialization post-mapper-creation steps.

This is a template method called by the MapperProperty object’s init() method.

extension_type = symbol('NOT_EXTENSION')¶

init()¶: inherited from the init() method of MapperProperty

Called after all mappers are created to assemble relationships between mappers and perform other post-mapper-creation initialization steps.

merge(session, source_state, source_dict, dest_state, dest_dict, load, _recursive, _resolve_conflict_map)¶: inherited from the merge() method of MapperProperty

Merge the attribute represented by this MapperProperty from source to destination object.

post_instrument_class(mapper)¶

inherited from the post_instrument_class() method of MapperProperty

Perform instrumentation adjustments that need to occur after init() has completed.

The given Mapper is the Mapper invoking the operation, which may not be the same Mapper as self.parent in an inheritance scenario; however, Mapper will always at least be a sub-mapper of self.parent.

This method is typically used by StrategizedProperty, which delegates it to LoaderStrategy.init_class_attribute() to perform final setup on the class-bound InstrumentedAttribute.

setup(context, entity, path, adapter, **kwargs)¶

inherited from the setup() method of MapperProperty

Called by Query for the purposes of constructing a SQL statement.

Each MapperProperty associated with the target mapper processes the statement referenced by the query context, adding columns and/or criterion as appropriate.

class sqlalchemy.orm.query.QueryContext(query)¶

class sqlalchemy.orm.attributes.QueryableAttribute(class_, key, impl=None, comparator=None, parententity=None, of_type=None)¶

Bases: sqlalchemy.orm.base._MappedAttribute, sqlalchemy.orm.base.InspectionAttr, sqlalchemy.orm.interfaces.PropComparator

Base class for descriptor objects that intercept attribute events on behalf of a MapperProperty object. The actual MapperProperty is accessible via the QueryableAttribute.property attribute.

InstrumentedAttribute

MapperProperty

Mapper.attrs

__eq__(other)¶

inherited from the __eq__() method of ColumnOperators

Implement the == operator.

In a column context, produces the clause a = b. If the target is None, produces a IS NULL.

__le__(other)¶

inherited from the __le__() method of ColumnOperators

Implement the <= operator.

In a column context, produces the clause a <= b.

__lt__(other)¶

inherited from the __lt__() method of ColumnOperators

Implement the < operator.

In a column context, produces the clause a < b.

__ne__(other)¶

inherited from the __ne__() method of ColumnOperators

Implement the != operator.

In a column context, produces the clause a != b. If the target is None, produces a IS NOT NULL.

adapter¶: inherited from the adapter attribute of PropComparator

Produce a callable that adapts column expressions to suit an aliased version of this comparator.

all_()¶: inherited from the all_() method of ColumnOperators

Produce a all_() clause against the parent object.

버전 1.1에 추가.

any(criterion=None, **kwargs)¶

inherited from the any() method of PropComparator

Return true if this collection contains any member that meets the given criterion.

The usual implementation of any() is RelationshipProperty.Comparator.any().

매개 변수:	criterion¶ – an optional ClauseElement formulated against the member class’ table or attributes. **kwargs¶ – key/value pairs corresponding to member class attribute names which will be compared via equality to the corresponding values.

any_()¶: inherited from the any_() method of ColumnOperators

Produce a any_() clause against the parent object.

버전 1.1에 추가.

asc()¶: inherited from the asc() method of ColumnOperators

Produce a asc() clause against the parent object.

between(cleft, cright, symmetric=False)¶: inherited from the between() method of ColumnOperators

Produce a between() clause against the parent object, given the lower and upper range.

collate(collation)¶: inherited from the collate() method of ColumnOperators

Produce a collate() clause against the parent object, given the collation string.

concat(other)¶

inherited from the concat() method of ColumnOperators

Implement the ‘concat’ operator.

In a column context, produces the clause a || b, or uses the concat() operator on MySQL.

contains(other, **kwargs)¶

inherited from the contains() method of ColumnOperators

Implement the ‘contains’ operator.

In a column context, produces the clause LIKE '%<other>%'

desc()¶: inherited from the desc() method of ColumnOperators

Produce a desc() clause against the parent object.

distinct()¶: inherited from the distinct() method of ColumnOperators

Produce a distinct() clause against the parent object.

endswith(other, **kwargs)¶

inherited from the endswith() method of ColumnOperators

Implement the ‘endswith’ operator.

In a column context, produces the clause LIKE '%<other>'

extension_type = symbol('NOT_EXTENSION')¶

has(criterion=None, **kwargs)¶

inherited from the has() method of PropComparator

Return true if this element references a member which meets the given criterion.

The usual implementation of has() is RelationshipProperty.Comparator.has().

매개 변수:	criterion¶ – an optional ClauseElement formulated against the member class’ table or attributes. **kwargs¶ – key/value pairs corresponding to member class attribute names which will be compared via equality to the corresponding values.

ilike(other, escape=None)¶

inherited from the ilike() method of ColumnOperators

Implement the ilike operator.

In a column context, produces the clause a ILIKE other.

E.g.:

select([sometable]).where(sometable.c.column.ilike("%foobar%"))

매개 변수:	other¶ – expression to be compared escape¶ – optional escape character, renders the `ESCAPE` keyword, e.g.: somecolumn.ilike("foo/%bar", escape="/")

in_(other)¶

inherited from the in_() method of ColumnOperators

Implement the in operator.

In a column context, produces the clause a IN other. “other” may be a tuple/list of column expressions, or a select() construct.

info¶

Return the ‘info’ dictionary for the underlying SQL element.

The behavior here is as follows:

If the attribute is a column-mapped property, i.e. ColumnProperty, which is mapped directly to a schema-level Column object, this attribute will return the SchemaItem.info dictionary associated with the core-level Column object.
If the attribute is a ColumnProperty but is mapped to any other kind of SQL expression other than a Column, the attribute will refer to the MapperProperty.info dictionary associated directly with the ColumnProperty, assuming the SQL expression itself does not have its own .info attribute (which should be the case, unless a user-defined SQL construct has defined one).
If the attribute refers to any other kind of MapperProperty, including RelationshipProperty, the attribute will refer to the MapperProperty.info dictionary associated with that MapperProperty.
To access the MapperProperty.info dictionary of the MapperProperty unconditionally, including for a ColumnProperty that’s associated directly with a schema.Column, the attribute can be referred to using QueryableAttribute.property attribute, as MyClass.someattribute.property.info.

버전 0.8.0에 추가.

SchemaItem.info

MapperProperty.info

is_(other)¶

inherited from the is_() method of ColumnOperators

Implement the IS operator.

Normally, IS is generated automatically when comparing to a value of None, which resolves to NULL. However, explicit usage of IS may be desirable if comparing to boolean values on certain platforms.

버전 0.7.9에 추가.

isnot(other)¶

inherited from the isnot() method of ColumnOperators

Implement the IS NOT operator.

Normally, IS NOT is generated automatically when comparing to a value of None, which resolves to NULL. However, explicit usage of IS NOT may be desirable if comparing to boolean values on certain platforms.

버전 0.7.9에 추가.

like(other, escape=None)¶

inherited from the like() method of ColumnOperators

Implement the like operator.

In a column context, produces the clause a LIKE other.

E.g.:

select([sometable]).where(sometable.c.column.like("%foobar%"))

매개 변수:	other¶ – expression to be compared escape¶ – optional escape character, renders the `ESCAPE` keyword, e.g.: somecolumn.like("foo/%bar", escape="/")

match(other, **kwargs)¶

inherited from the match() method of ColumnOperators

Implements a database-specific ‘match’ operator.

match() attempts to resolve to a MATCH-like function or operator provided by the backend. Examples include:

Postgresql - renders x @@ to_tsquery(y)
MySQL - renders MATCH (x) AGAINST (y IN BOOLEAN MODE)
Oracle - renders CONTAINS(x, y)
other backends may provide special implementations.
Backends without any special implementation will emit the operator as “MATCH”. This is compatible with SQlite, for example.

notilike(other, escape=None)¶

inherited from the notilike() method of ColumnOperators

implement the NOT ILIKE operator.

This is equivalent to using negation with ColumnOperators.ilike(), i.e. ~x.ilike(y).

버전 0.8에 추가.

notin_(other)¶

inherited from the notin_() method of ColumnOperators

implement the NOT IN operator.

This is equivalent to using negation with ColumnOperators.in_(), i.e. ~x.in_(y).

버전 0.8에 추가.

notlike(other, escape=None)¶

inherited from the notlike() method of ColumnOperators

implement the NOT LIKE operator.

This is equivalent to using negation with ColumnOperators.like(), i.e. ~x.like(y).

버전 0.8에 추가.

nullsfirst()¶: inherited from the nullsfirst() method of ColumnOperators

Produce a nullsfirst() clause against the parent object.

nullslast()¶: inherited from the nullslast() method of ColumnOperators

Produce a nullslast() clause against the parent object.

op(opstring, precedence=0, is_comparison=False)¶

inherited from the op() method of Operators

produce a generic operator function.

e.g.:

somecolumn.op("*")(5)

produces:

somecolumn * 5

This function can also be used to make bitwise operators explicit. For example:

somecolumn.op('&')(0xff)

is a bitwise AND of the value in somecolumn.

매개 변수:

operator¶ – a string which will be output as the infix operator between this element and the expression passed to the generated function.
precedence¶ –
precedence to apply to the operator, when parenthesizing expressions. A lower number will cause the expression to be parenthesized when applied against another operator with higher precedence. The default value of 0 is lower than all operators except for the comma (,) and AS operators. A value of 100 will be higher or equal to all operators, and -100 will be lower than or equal to all operators.

버전 0.8에 추가: - added the ‘precedence’ argument.
is_comparison¶ –
if True, the operator will be considered as a “comparison” operator, that is which evaluates to a boolean true/false value, like ==, >, etc. This flag should be set so that ORM relationships can establish that the operator is a comparison operator when used in a custom join condition.

버전 0.9.2에 추가: - added the Operators.op.is_comparison flag.