diff options
Diffstat (limited to 'lib/sqlalchemy/orm/query.py')
| -rw-r--r-- | lib/sqlalchemy/orm/query.py | 171 |
1 files changed, 84 insertions, 87 deletions
diff --git a/lib/sqlalchemy/orm/query.py b/lib/sqlalchemy/orm/query.py index a34fd882a..ca334e273 100644 --- a/lib/sqlalchemy/orm/query.py +++ b/lib/sqlalchemy/orm/query.py @@ -27,7 +27,7 @@ from . import ( from .util import ( AliasedClass, ORMAdapter, _entity_descriptor, PathRegistry, _is_aliased_class, _is_mapped_class, _orm_columns, - join as orm_join,with_parent, aliased + join as orm_join, with_parent, aliased ) from .. import sql, util, log, exc as sa_exc, inspect, inspection, \ types as sqltypes @@ -54,6 +54,7 @@ def _generative(*assertions): _path_registry = PathRegistry.root + class Query(object): """ORM-level SQL construction object. @@ -177,7 +178,6 @@ class Query(object): self._from_obj_alias = sql_util.ColumnAdapter( self._from_obj[0], equivs) - def _reset_polymorphic_adapter(self, mapper): for m2 in mapper._with_polymorphic_mappers: self._polymorphic_adapters.pop(m2, None) @@ -274,7 +274,6 @@ class Query(object): return self._select_from_entity or \ self._entity_zero().entity_zero - @property def _mapper_entities(self): # TODO: this is wrong, its hardcoded to "primary entity" when @@ -325,7 +324,6 @@ class Query(object): ) return self._entity_zero() - def __all_equivs(self): equivs = {} for ent in self._mapper_entities: @@ -540,10 +538,9 @@ class Query(object): return self.enable_eagerloads(False).statement.label(name) - def as_scalar(self): - """Return the full SELECT statement represented by this :class:`.Query`, converted - to a scalar subquery. + """Return the full SELECT statement represented by this + :class:`.Query`, converted to a scalar subquery. Analogous to :meth:`sqlalchemy.sql.SelectBaseMixin.as_scalar`. @@ -618,7 +615,8 @@ class Query(object): @property def whereclause(self): - """A readonly attribute which returns the current WHERE criterion for this Query. + """A readonly attribute which returns the current WHERE criterion for + this Query. This returned value is a SQL expression construct, or ``None`` if no criterion has been established. @@ -648,11 +646,11 @@ class Query(object): :meth:`.Query.with_polymorphic` applies transformations to the "main" mapped class represented by this :class:`.Query`. The "main" mapped class here means the :class:`.Query` - object's first argument is a full class, i.e. ``session.query(SomeClass)``. - These transformations allow additional tables to be present - in the FROM clause so that columns for a joined-inheritance - subclass are available in the query, both for the purposes - of load-time efficiency as well as the ability to use + object's first argument is a full class, i.e. + ``session.query(SomeClass)``. These transformations allow additional + tables to be present in the FROM clause so that columns for a + joined-inheritance subclass are available in the query, both for the + purposes of load-time efficiency as well as the ability to use these columns at query time. See the documentation section :ref:`with_polymorphic` for @@ -783,7 +781,8 @@ class Query(object): not mapper.always_refresh and \ self._lockmode is None: - instance = loading.get_from_identity(self.session, key, attributes.PASSIVE_OFF) + instance = loading.get_from_identity( + self.session, key, attributes.PASSIVE_OFF) if instance is not None: # reject calls for id in identity map but class # mismatch. @@ -980,8 +979,8 @@ class Query(object): @_generative() def with_entities(self, *entities): - """Return a new :class:`.Query` replacing the SELECT list with the given - entities. + """Return a new :class:`.Query` replacing the SELECT list with the + given entities. e.g.:: @@ -1006,7 +1005,6 @@ class Query(object): """ self._set_entities(entities) - @_generative() def add_columns(self, *column): """Add one or more column expressions to the list @@ -1024,13 +1022,13 @@ class Query(object): ":meth:`.add_column` is superseded by :meth:`.add_columns`", False) def add_column(self, column): - """Add a column expression to the list of result columns to be returned. + """Add a column expression to the list of result columns to be + returned. Pending deprecation: :meth:`.add_column` will be superseded by :meth:`.add_columns`. """ - return self.add_columns(column) def options(self, *args): @@ -1340,9 +1338,8 @@ class Query(object): """ - return self._from_selectable( - expression.union(*([self]+ list(q)))) + expression.union(*([self] + list(q)))) def union_all(self, *q): """Produce a UNION ALL of this Query against one or more queries. @@ -1352,7 +1349,7 @@ class Query(object): """ return self._from_selectable( - expression.union_all(*([self]+ list(q))) + expression.union_all(*([self] + list(q))) ) def intersect(self, *q): @@ -1363,7 +1360,7 @@ class Query(object): """ return self._from_selectable( - expression.intersect(*([self]+ list(q))) + expression.intersect(*([self] + list(q))) ) def intersect_all(self, *q): @@ -1374,7 +1371,7 @@ class Query(object): """ return self._from_selectable( - expression.intersect_all(*([self]+ list(q))) + expression.intersect_all(*([self] + list(q))) ) def except_(self, *q): @@ -1385,7 +1382,7 @@ class Query(object): """ return self._from_selectable( - expression.except_(*([self]+ list(q))) + expression.except_(*([self] + list(q))) ) def except_all(self, *q): @@ -1396,7 +1393,7 @@ class Query(object): """ return self._from_selectable( - expression.except_all(*([self]+ list(q))) + expression.except_all(*([self] + list(q))) ) def join(self, *props, **kwargs): @@ -1422,9 +1419,9 @@ class Query(object): In the above example we refer to ``User.addresses`` as passed to :meth:`~.Query.join` as the *on clause*, that is, it indicates how the "ON" portion of the JOIN should be constructed. For a - single-entity query such as the one above (i.e. we start by selecting only from - ``User`` and nothing else), the relationship can also be specified by its - string name:: + single-entity query such as the one above (i.e. we start by selecting + only from ``User`` and nothing else), the relationship can also be + specified by its string name:: q = session.query(User).join("addresses") @@ -1434,8 +1431,9 @@ class Query(object): q = session.query(User).join("orders", "items", "keywords") - The above would be shorthand for three separate calls to :meth:`~.Query.join`, - each using an explicit attribute to indicate the source entity:: + The above would be shorthand for three separate calls to + :meth:`~.Query.join`, each using an explicit attribute to indicate + the source entity:: q = session.query(User).\\ join(User.orders).\\ @@ -1511,25 +1509,26 @@ class Query(object): There is a lot of flexibility in what the "target" can be when using :meth:`~.Query.join`. As noted previously, it also accepts - :class:`.Table` constructs and other selectables such as :func:`.alias` - and :func:`.select` constructs, with either the one or two-argument forms:: + :class:`.Table` constructs and other selectables such as + :func:`.alias` and :func:`.select` constructs, with either the one + or two-argument forms:: addresses_q = select([Address.user_id]).\\ - where(Address.email_address.endswith("@bar.com")).\\ - alias() + where(Address.email_address.endswith("@bar.com")).\\ + alias() q = session.query(User).\\ join(addresses_q, addresses_q.c.user_id==User.id) :meth:`~.Query.join` also features the ability to *adapt* a - :meth:`~sqlalchemy.orm.relationship` -driven ON clause to the target selectable. - Below we construct a JOIN from ``User`` to a subquery against ``Address``, allowing - the relationship denoted by ``User.addresses`` to *adapt* itself - to the altered target:: + :meth:`~sqlalchemy.orm.relationship` -driven ON clause to the target + selectable. Below we construct a JOIN from ``User`` to a subquery + against ``Address``, allowing the relationship denoted by + ``User.addresses`` to *adapt* itself to the altered target:: address_subq = session.query(Address).\\ - filter(Address.email_address == 'ed@foo.com').\\ - subquery() + filter(Address.email_address == 'ed@foo.com').\\ + subquery() q = session.query(User).join(address_subq, User.addresses) @@ -1811,7 +1810,7 @@ class Query(object): if not create_aliases and prop: self._update_joinpoint({ '_joinpoint_entity': right, - 'prev':((left, right, prop.key), self._joinpoint) + 'prev': ((left, right, prop.key), self._joinpoint) }) else: self._joinpoint = { @@ -2051,7 +2050,7 @@ class Query(object): if item == -1: return list(self)[-1] else: - return list(self[item:item+1])[0] + return list(self[item:item + 1])[0] @_generative(_no_statement_condition) def slice(self, start, stop): @@ -2261,8 +2260,8 @@ class Query(object): def _execute_and_instances(self, querycontext): conn = self._connection_from_session( - mapper = self._mapper_zero_or_none(), - clause = querycontext.statement, + mapper=self._mapper_zero_or_none(), + clause=querycontext.statement, close_with_result=True) result = conn.execute(querycontext.statement, self._params) @@ -2330,20 +2329,20 @@ class Query(object): return loading.instances(self, cursor, context) - def merge_result(self, iterator, load=True): """Merge a result into this :class:`.Query` object's Session. - Given an iterator returned by a :class:`.Query` of the same structure as this - one, return an identical iterator of results, with all mapped - instances merged into the session using :meth:`.Session.merge`. This is an - optimized method which will merge all mapped instances, preserving the - structure of the result rows and unmapped columns with less method - overhead than that of calling :meth:`.Session.merge` explicitly for each - value. + Given an iterator returned by a :class:`.Query` of the same structure + as this one, return an identical iterator of results, with all mapped + instances merged into the session using :meth:`.Session.merge`. This + is an optimized method which will merge all mapped instances, + preserving the structure of the result rows and unmapped columns with + less method overhead than that of calling :meth:`.Session.merge` + explicitly for each value. The structure of the results is determined based on the column list of - this :class:`.Query` - if these do not correspond, unchecked errors will occur. + this :class:`.Query` - if these do not correspond, unchecked errors + will occur. The 'load' argument is the same as that of :meth:`.Session.merge`. @@ -2359,12 +2358,12 @@ class Query(object): @property def _select_args(self): return { - 'limit':self._limit, - 'offset':self._offset, - 'distinct':self._distinct, - 'prefixes':self._prefixes, - 'group_by':self._group_by or None, - 'having':self._having + 'limit': self._limit, + 'offset': self._offset, + 'distinct': self._distinct, + 'prefixes': self._prefixes, + 'group_by': self._group_by or None, + 'having': self._having } @property @@ -2435,8 +2434,8 @@ class Query(object): removed from the session. Matched objects are removed from the session. - ``'evaluate'`` - Evaluate the query's criteria in Python straight on - the objects in the session. If evaluation of the criteria isn't + ``'evaluate'`` - Evaluate the query's criteria in Python straight + on the objects in the session. If evaluation of the criteria isn't implemented, an error is raised. In that case you probably want to use the 'fetch' strategy as a fallback. @@ -2487,8 +2486,8 @@ class Query(object): objects that are matched by the update query. The updated attributes are expired on matched objects. - ``'evaluate'`` - Evaluate the Query's criteria in Python straight on - the objects in the session. If evaluation of the criteria isn't + ``'evaluate'`` - Evaluate the Query's criteria in Python straight + on the objects in the session. If evaluation of the criteria isn't implemented, an exception is raised. The expression evaluator currently doesn't account for differing @@ -2522,7 +2521,6 @@ class Query(object): update_op.exec_() return update_op.rowcount - _lockmode_lookup = { 'read': 'read', 'read_nowait': 'read_nowait', @@ -2708,6 +2706,7 @@ class Query(object): inspection._self_inspects(Query) + class _QueryEntity(object): """represent an entity column returned within a Query result.""" @@ -2726,6 +2725,7 @@ class _QueryEntity(object): q.__dict__ = self.__dict__.copy() return q + class _MapperEntity(_QueryEntity): """mapper/class/AliasedClass entity""" @@ -2739,7 +2739,7 @@ class _MapperEntity(_QueryEntity): def setup_entity(self, ext_info, aliased_adapter): self.mapper = ext_info.mapper self.aliased_adapter = aliased_adapter - self.selectable = ext_info.selectable + self.selectable = ext_info.selectable self.is_aliased_class = ext_info.is_aliased_class self._with_polymorphic = ext_info.with_polymorphic_mappers self._polymorphic_discriminator = \ @@ -2829,28 +2829,27 @@ class _MapperEntity(_QueryEntity): # require row aliasing unconditionally. if not adapter and self.mapper._requires_row_aliasing: adapter = sql_util.ColumnAdapter( - self.selectable, - self.mapper._equivalent_columns) + self.selectable, + self.mapper._equivalent_columns) if self.primary_entity: _instance = loading.instance_processor( - self.mapper, - context, - self.path, - adapter, - only_load_props=query._only_load_props, - refresh_state=context.refresh_state, - polymorphic_discriminator= - self._polymorphic_discriminator + self.mapper, + context, + self.path, + adapter, + only_load_props=query._only_load_props, + refresh_state=context.refresh_state, + polymorphic_discriminator=self._polymorphic_discriminator ) else: _instance = loading.instance_processor( - self.mapper, - context, - self.path, - adapter, - polymorphic_discriminator= - self._polymorphic_discriminator) + self.mapper, + context, + self.path, + adapter, + polymorphic_discriminator=self._polymorphic_discriminator + ) return _instance, self._label_name @@ -2902,6 +2901,7 @@ class _MapperEntity(_QueryEntity): def __str__(self): return str(self.mapper) + class _ColumnEntity(_QueryEntity): """Column/expression based entity.""" @@ -2931,7 +2931,6 @@ class _ColumnEntity(_QueryEntity): if c is not column: return - if not isinstance(column, sql.ColumnElement): raise sa_exc.InvalidRequestError( "SQL expression, column, or mapped entity " @@ -2981,7 +2980,6 @@ class _ColumnEntity(_QueryEntity): else: self.entity_zero = None - @property def entity_zero_or_selectable(self): if self.entity_zero is not None: @@ -2995,7 +2993,6 @@ class _ColumnEntity(_QueryEntity): def type(self): return self.column.type - def adapt_to_selectable(self, query, sel): c = _ColumnEntity(query, sel.corresponding_column(self.column)) c._label_name = self._label_name @@ -3040,8 +3037,10 @@ class _ColumnEntity(_QueryEntity): def __str__(self): return str(self.column) + log.class_logger(Query) + class QueryContext(object): multi_row_eager_loaders = False adapter = None @@ -3089,5 +3088,3 @@ class AliasOption(interfaces.MapperOption): else: alias = self.alias query._from_obj_alias = sql_util.ColumnAdapter(alias) - - |