diff options
Diffstat (limited to 'lib/sqlalchemy/orm/mapper.py')
| -rw-r--r-- | lib/sqlalchemy/orm/mapper.py | 191 |
1 files changed, 119 insertions, 72 deletions
diff --git a/lib/sqlalchemy/orm/mapper.py b/lib/sqlalchemy/orm/mapper.py index 5a2ca6ed4..b1a6b1a33 100644 --- a/lib/sqlalchemy/orm/mapper.py +++ b/lib/sqlalchemy/orm/mapper.py @@ -151,17 +151,7 @@ class Mapper(object): self.allow_partial_pks = allow_partial_pks - if with_polymorphic == '*': - self.with_polymorphic = ('*', None) - elif isinstance(with_polymorphic, (tuple, list)): - if isinstance(with_polymorphic[0], (basestring, tuple, list)): - self.with_polymorphic = with_polymorphic - else: - self.with_polymorphic = (with_polymorphic, None) - elif with_polymorphic is not None: - raise sa_exc.ArgumentError("Invalid setting for with_polymorphic") - else: - self.with_polymorphic = None + self._set_with_polymorphic(with_polymorphic) if isinstance(self.local_table, expression._SelectBase): raise sa_exc.InvalidRequestError( @@ -225,10 +215,10 @@ class Mapper(object): local_table = None """The :class:`.Selectable` which this :class:`.Mapper` manages. - + Typically is an instance of :class:`.Table` or :class:`.Alias`. May also be ``None``. - + The "local" table is the selectable that the :class:`.Mapper` is directly responsible for managing from an attribute access and flush perspective. For @@ -239,15 +229,15 @@ class Mapper(object): single-table inheriting mapper, local_table will be ``None``. See also :attr:`~.Mapper.mapped_table`. - + """ mapped_table = None """The :class:`.Selectable` to which this :class:`.Mapper` is mapped. - + Typically an instance of :class:`.Table`, :class:`.Join`, or - :class:`.Alias`. - + :class:`.Alias`. + The "mapped" table is the selectable that the mapper selects from during queries. For non-inheriting mappers, the mapped table is the same as the "local" table. @@ -255,99 +245,99 @@ class Mapper(object): full :class:`.Join` representing full rows for this particular subclass. For single-table inheritance mappers, mapped_table references the base table. - + See also :attr:`~.Mapper.local_table`. - + """ inherits = None """References the :class:`.Mapper` which this :class:`.Mapper` inherits from, if any. - This is a *read only* attribute determined during mapper construction. + This is a *read only* attribute determined during mapper construction. Behavior is undefined if directly modified. - + """ configured = None """Represent ``True`` if this :class:`.Mapper` has been configured. - This is a *read only* attribute determined during mapper construction. + This is a *read only* attribute determined during mapper construction. Behavior is undefined if directly modified. - + See also :func:`.configure_mappers`. - + """ concrete = None """Represent ``True`` if this :class:`.Mapper` is a concrete inheritance mapper. - This is a *read only* attribute determined during mapper construction. + This is a *read only* attribute determined during mapper construction. Behavior is undefined if directly modified. - + """ tables = None """An iterable containing the collection of :class:`.Table` objects which this :class:`.Mapper` is aware of. - + If the mapper is mapped to a :class:`.Join`, or an :class:`.Alias` representing a :class:`.Select`, the individual :class:`.Table` objects that comprise the full construct will be represented here. - This is a *read only* attribute determined during mapper construction. + This is a *read only* attribute determined during mapper construction. Behavior is undefined if directly modified. - + """ primary_key = None """An iterable containing the collection of :class:`.Column` objects which comprise the 'primary key' of the mapped table, from the perspective of this :class:`.Mapper`. - + This list is against the selectable in :attr:`~.Mapper.mapped_table`. In the case of inheriting mappers, some columns may be managed by a superclass mapper. For example, in the case of a :class:`.Join`, the primary key is determined by all of the primary key columns across all tables referenced by the :class:`.Join`. - + The list is also not necessarily the same as the primary key column collection associated with the underlying tables; the :class:`.Mapper` features a ``primary_key`` argument that can override what the :class:`.Mapper` considers as primary key columns. - This is a *read only* attribute determined during mapper construction. + This is a *read only* attribute determined during mapper construction. Behavior is undefined if directly modified. - + """ class_ = None """The Python class which this :class:`.Mapper` maps. - This is a *read only* attribute determined during mapper construction. + This is a *read only* attribute determined during mapper construction. Behavior is undefined if directly modified. - + """ class_manager = None """The :class:`.ClassManager` which maintains event listeners and class-bound descriptors for this :class:`.Mapper`. - This is a *read only* attribute determined during mapper construction. + This is a *read only* attribute determined during mapper construction. Behavior is undefined if directly modified. """ single = None """Represent ``True`` if this :class:`.Mapper` is a single table - inheritance mapper. - + inheritance mapper. + :attr:`~.Mapper.local_table` will be ``None`` if this flag is set. - - This is a *read only* attribute determined during mapper construction. + + This is a *read only* attribute determined during mapper construction. Behavior is undefined if directly modified. - + """ non_primary = None @@ -355,35 +345,35 @@ class Mapper(object): mapper, e.g. a mapper that is used only to selet rows but not for persistence management. - This is a *read only* attribute determined during mapper construction. + This is a *read only* attribute determined during mapper construction. Behavior is undefined if directly modified. - + """ polymorphic_on = None """The :class:`.Column` specified as the ``polymorphic_on`` column for this :class:`.Mapper`, within an inheritance scenario. - + This attribute may also be of other types besides :class:`.Column` in a future SQLAlchemy release. - This is a *read only* attribute determined during mapper construction. + This is a *read only* attribute determined during mapper construction. Behavior is undefined if directly modified. - + """ polymorphic_map = None """A mapping of "polymorphic identity" identifiers mapped to :class:`.Mapper` instances, within an inheritance scenario. - + The identifiers can be of any type which is comparable to the type of column represented by :attr:`~.Mapper.polymorphic_on`. - + An inheritance chain of mappers will all reference the same polymorphic map object. The object is used to correlate incoming result rows to target mappers. - This is a *read only* attribute determined during mapper construction. + This is a *read only* attribute determined during mapper construction. Behavior is undefined if directly modified. """ @@ -391,32 +381,32 @@ class Mapper(object): polymorphic_identity = None """Represent an identifier which is matched against the :attr:`~.Mapper.polymorphic_on` column during result row loading. - + Used only with inheritance, this object can be of any type which is comparable to the type of column represented by :attr:`~.Mapper.polymorphic_on`. - - This is a *read only* attribute determined during mapper construction. + + This is a *read only* attribute determined during mapper construction. Behavior is undefined if directly modified. - + """ base_mapper = None """The base-most :class:`.Mapper` in an inheritance chain. - + In a non-inheriting scenario, this attribute will always be this :class:`.Mapper`. In an inheritance scenario, it references the :class:`.Mapper` which is parent to all other :class:`.Mapper` objects in the inheritance chain. - This is a *read only* attribute determined during mapper construction. + This is a *read only* attribute determined during mapper construction. Behavior is undefined if directly modified. - + """ columns = None """A collection of :class:`.Column` or other scalar expression objects maintained by this :class:`.Mapper`. - + The collection behaves the same as that of the ``c`` attribute on any :class:`.Table` object, except that only those columns included in this mapping are present, and are keyed based on the attribute name @@ -424,9 +414,9 @@ class Mapper(object): :class:`.Column` itself. Additionally, scalar expressions mapped by :func:`.column_property` are also present here. - This is a *read only* attribute determined during mapper construction. + This is a *read only* attribute determined during mapper construction. Behavior is undefined if directly modified. - + """ validators = None @@ -530,16 +520,6 @@ class Mapper(object): if self.polymorphic_identity is not None: self.polymorphic_map[self.polymorphic_identity] = self - if self.polymorphic_on is None: - for mapper in self.iterate_to_root(): - # try to set up polymorphic on using - # correesponding_column(); else leave - # as None - if mapper.polymorphic_on is not None: - self.polymorphic_on = \ - self.mapped_table.corresponding_column( - mapper.polymorphic_on) - break else: self._all_tables = set() self.base_mapper = self @@ -553,6 +533,59 @@ class Mapper(object): "Mapper '%s' does not have a mapped_table specified." % self) + def _set_with_polymorphic(self, with_polymorphic): + if with_polymorphic == '*': + self.with_polymorphic = ('*', None) + elif isinstance(with_polymorphic, (tuple, list)): + if isinstance(with_polymorphic[0], (basestring, tuple, list)): + self.with_polymorphic = with_polymorphic + else: + self.with_polymorphic = (with_polymorphic, None) + elif with_polymorphic is not None: + raise sa_exc.ArgumentError("Invalid setting for with_polymorphic") + else: + self.with_polymorphic = None + + if isinstance(self.local_table, expression._SelectBase): + raise sa_exc.InvalidRequestError( + "When mapping against a select() construct, map against " + "an alias() of the construct instead." + "This because several databases don't allow a " + "SELECT from a subquery that does not have an alias." + ) + + if self.with_polymorphic and \ + isinstance(self.with_polymorphic[1], + expression._SelectBase): + self.with_polymorphic = (self.with_polymorphic[0], + self.with_polymorphic[1].alias()) + if self.configured: + self._expire_memoizations() + + def _set_concrete_base(self, mapper): + """Set the given :class:`.Mapper` as the 'inherits' for this :class:`.Mapper`, + assuming this :class:`.Mapper` is concrete and does not already have + an inherits.""" + + assert self.concrete + assert not self.inherits + assert isinstance(mapper, Mapper) + self.inherits = mapper + self.inherits.polymorphic_map.update(self.polymorphic_map) + self.polymorphic_map = self.inherits.polymorphic_map + for mapper in self.iterate_to_root(): + if mapper.polymorphic_on is not None: + mapper._requires_row_aliasing = True + self.batch = self.inherits.batch + self.base_mapper = self.inherits.base_mapper + self.inherits._inheriting_mappers.add(self) + self.passive_updates = self.inherits.passive_updates + self._all_tables = self.inherits._all_tables + + def _set_polymorphic_on(self, polymorphic_on): + self.polymorphic_on = polymorphic_on + self._configure_polymorphic_setter(True) + def _configure_legacy_instrument_class(self): if self.inherits: @@ -818,7 +851,7 @@ class Mapper(object): init=False, setparent=True) - def _configure_polymorphic_setter(self): + def _configure_polymorphic_setter(self, init=False): """Configure an attribute on the mapper representing the 'polymorphic_on' column, if applicable, and not already generated by _configure_properties (which is typical). @@ -834,6 +867,17 @@ class Mapper(object): # but we need it for the base mapper setter = False + if self.polymorphic_on is None: + for mapper in self.iterate_to_root(): + # try to set up polymorphic on using + # correesponding_column(); else leave + # as None + if mapper.polymorphic_on is not None: + self.polymorphic_on = \ + self.mapped_table.corresponding_column( + mapper.polymorphic_on) + break + if self.polymorphic_on is not None: setter = True @@ -861,7 +905,7 @@ class Mapper(object): self._configure_property( col.key, properties.ColumnProperty(col, _instrument=instrument), - init=False, setparent=True) + init=init, setparent=True) polymorphic_key = col.key else: polymorphic_key = self._columntoproperty[self.polymorphic_on].key @@ -2714,6 +2758,7 @@ def configure_mappers(): if not _new_mappers: return + _call_configured = None _COMPILE_MUTEX.acquire() try: global _already_compiling @@ -2744,6 +2789,7 @@ def configure_mappers(): mapper._post_configure_properties() mapper._expire_memoizations() mapper.dispatch.mapper_configured(mapper, mapper.class_) + _call_configured = mapper except: exc = sys.exc_info()[1] if not hasattr(exc, '_configure_failed'): @@ -2755,7 +2801,8 @@ def configure_mappers(): _already_compiling = False finally: _COMPILE_MUTEX.release() - + if _call_configured is not None: + _call_configured.dispatch.after_configured() def reconstructor(fn): """Decorate a method as the 'reconstructor' hook. |