我有以下型号：
class Shipment(TenantModel):
id = models.BigIntegerField(primary_key=True)
adjusted_ordered_at = models.DateTimeField()
created_at = models.DateTimeField()
shipped_at = models.DateTimeField(null=True)
store = models.ForeignKey(Store, on_delete=models.CASCADE)
tenant_id = 'store_id'
class Meta:
ordering = ['created_at', 'status']
unique_together = ['id', 'store']
def __str__(self):
return "%s, %s" % (self.id, self.status)
class Fulfillment(TenantModel):
id = models.BigIntegerField(primary_key=True)
shipment = TenantForeignKey('Shipment', on_delete=models.CASCADE)
product_instance = TenantForeignKey(ProductInstance,
on_delete=models.CASCADE)
class ProductInstance(TenantModel):
id = models.BigIntegerField(primary_key=True)
product = TenantForeignKey(Product, on_delete=models.CASCADE)
class Product(TenantModel):
id = models.BigIntegerField(primary_key=True)
product_type = models.CharField(max_length=32)
我要过滤所有产品类型不等于“订阅”的货件。
由此获得正确的结果：
Shipment.objects.filter(Q(fulfillment__product_instance__product__product_type='subscription'))
获取AttributeError: 'NoneType' object has no attribute 'startswith'：
Shipment.objects.filter(~Q(fulfillment__product_instance__product__product_type='subscription'))
这是堆栈跟踪
AttributeError Traceback (most recent call last)
/usr/local/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
700 type_pprinters=self.type_printers,
701 deferred_pprinters=self.deferred_printers)
--> 702 printer.pretty(obj)
703 printer.flush()
704 return stream.getvalue()
/usr/local/lib/python3.6/site-packages/IPython/lib/pretty.py in pretty(self, obj)
398 if cls is not object \
399 and callable(cls.__dict__.get('__repr__')):
--> 400 return _repr_pprint(obj, self, cycle)
401
402 return _default_pprint(obj, self, cycle)
/usr/local/lib/python3.6/site-packages/IPython/lib/pretty.py in _repr_pprint(obj, p, cycle)
693 """A pprint that just redirects to the normal repr function."""
694 # Find newlines and replace them with p.break_()
--> 695 output = repr(obj)
696 for idx,output_line in enumerate(output.splitlines()):
697 if idx:
/usr/local/lib/python3.6/site-packages/django/db/models/query.py in __repr__(self)
242
243 def __repr__(self):
--> 244 data = list(self[:REPR_OUTPUT_SIZE + 1])
245 if len(data) > REPR_OUTPUT_SIZE:
246 data[-1] = "...(remaining elements truncated)..."
/usr/local/lib/python3.6/site-packages/django_multitenant/models.py in __iter__(self)
54 def __iter__(self):
55 # self.add_tenant_filters_with_joins()
---> 56 return super(TenantQuerySet,self).__iter__()
57
58 def aggregate(self, *args, **kwargs):
/usr/local/lib/python3.6/site-packages/django/db/models/query.py in __iter__(self)
266 - Responsible for turning the rows into model objects.
267 """
--> 268 self._fetch_all()
269 return iter(self._result_cache)
270
/usr/local/lib/python3.6/site-packages/django/db/models/query.py in _fetch_all(self)
1181 def _fetch_all(self):
1182 if self._result_cache is None:
-> 1183 self._result_cache = list(self._iterable_class(self))
1184 if self._prefetch_related_lookups and not self._prefetch_done:
1185 self._prefetch_related_objects()
/usr/local/lib/python3.6/site-packages/django/db/models/query.py in __iter__(self)
52 # Execute the query. This will also fill compiler.select, klass_info,
53 # and annotations.
---> 54 results = compiler.execute_sql(chunked_fetch=self.chunked_fetch, chunk_size=self.chunk_size)
55 select, klass_info, annotation_col_map = (compiler.select, compiler.klass_info,
56 compiler.annotation_col_map)
/usr/local/lib/python3.6/site-packages/django/db/models/sql/compiler.py in execute_sql(self, result_type, chunked_fetch, chunk_size)
1046 result_type = result_type or NO_RESULTS
1047 try:
-> 1048 sql, params = self.as_sql()
1049 if not sql:
1050 raise EmptyResultSet
/usr/local/lib/python3.6/site-packages/django/db/models/sql/compiler.py in as_sql(self, with_limits, with_col_aliases)
458 # (see docstring of get_from_clause() for details).
459 from_, f_params = self.get_from_clause()
--> 460 where, w_params = self.compile(self.where) if self.where is not None else ("", [])
461 having, h_params = self.compile(self.having) if self.having is not None else ("", [])
462 result = ['SELECT']
/usr/local/lib/python3.6/site-packages/django/db/models/sql/compiler.py in compile(self, node, select_format)
388 sql, params = vendor_impl(self, self.connection)
389 else:
--> 390 sql, params = node.as_sql(self, self.connection)
391 if select_format is FORCE or (select_format and not self.query.subquery):
392 return node.output_field.select_format(self, sql, params)
/usr/local/lib/python3.6/site-packages/django/db/models/sql/where.py in as_sql(self, compiler, connection)
79 for child in self.children:
80 try:
---> 81 sql, params = compiler.compile(child)
82 except EmptyResultSet:
83 empty_needed -= 1
/usr/local/lib/python3.6/site-packages/django/db/models/sql/compiler.py in compile(self, node, select_format)
388 sql, params = vendor_impl(self, self.connection)
389 else:
--> 390 sql, params = node.as_sql(self, self.connection)
391 if select_format is FORCE or (select_format and not self.query.subquery):
392 return node.output_field.select_format(self, sql, params)
/usr/local/lib/python3.6/site-packages/django/db/models/sql/where.py in as_sql(self, compiler, connection)
79 for child in self.children:
80 try:
---> 81 sql, params = compiler.compile(child)
82 except EmptyResultSet:
83 empty_needed -= 1
/usr/local/lib/python3.6/site-packages/django/db/models/sql/compiler.py in compile(self, node, select_format)
388 sql, params = vendor_impl(self, self.connection)
389 else:
--> 390 sql, params = node.as_sql(self, self.connection)
391 if select_format is FORCE or (select_format and not self.query.subquery):
392 return node.output_field.select_format(self, sql, params)
/usr/local/lib/python3.6/site-packages/django/db/models/lookups.py in as_sql(self, compiler, connection)
353 if self.rhs_is_direct_value() and max_in_list_size and len(self.rhs) > max_in_list_size:
354 return self.split_parameter_list_as_sql(compiler, connection)
--> 355 return super().as_sql(compiler, connection)
356
357 def split_parameter_list_as_sql(self, compiler, connection):
/usr/local/lib/python3.6/site-packages/django/db/models/lookups.py in as_sql(self, compiler, connection)
161 def as_sql(self, compiler, connection):
162 lhs_sql, params = self.process_lhs(compiler, connection)
--> 163 rhs_sql, rhs_params = self.process_rhs(compiler, connection)
164 params.extend(rhs_params)
165 rhs_sql = self.get_rhs_op(connection, rhs_sql)
/usr/local/lib/python3.6/site-packages/django/db/models/lookups.py in process_rhs(self, compiler, connection)
344 self.rhs.clear_select_clause()
345 self.rhs.add_fields(['pk'])
--> 346 return super().process_rhs(compiler, connection)
347
348 def get_rhs_op(self, connection, rhs):
/usr/local/lib/python3.6/site-packages/django/db/models/lookups.py in process_rhs(self, compiler, connection)
218 return self.batch_process_rhs(compiler, connection)
219 else:
--> 220 return super().process_rhs(compiler, connection)
221
222 def resolve_expression_parameter(self, compiler, connection, sql, param):
/usr/local/lib/python3.6/site-packages/django/db/models/lookups.py in process_rhs(self, compiler, connection)
90 value = value.resolve_expression(compiler.query)
91 if hasattr(value, 'as_sql'):
---> 92 sql, params = compiler.compile(value)
93 return '(' + sql + ')', params
94 else:
/usr/local/lib/python3.6/site-packages/django/db/models/sql/compiler.py in compile(self, node, select_format)
388 sql, params = vendor_impl(self, self.connection)
389 else:
--> 390 sql, params = node.as_sql(self, self.connection)
391 if select_format is FORCE or (select_format and not self.query.subquery):
392 return node.output_field.select_format(self, sql, params)
/usr/local/lib/python3.6/site-packages/django/db/models/sql/query.py in as_sql(self, compiler, connection)
1004
1005 def as_sql(self, compiler, connection):
-> 1006 return self.get_compiler(connection=connection).as_sql()
1007
1008 def resolve_lookup_value(self, value, can_reuse, allow_joins):
/usr/local/lib/python3.6/site-packages/django/db/models/sql/compiler.py in as_sql(self, with_limits, with_col_aliases)
458 # (see docstring of get_from_clause() for details).
459 from_, f_params = self.get_from_clause()
--> 460 where, w_params = self.compile(self.where) if self.where is not None else ("", [])
461 having, h_params = self.compile(self.having) if self.having is not None else ("", [])
462 result = ['SELECT']
/usr/local/lib/python3.6/site-packages/django/db/models/sql/compiler.py in compile(self, node, select_format)
388 sql, params = vendor_impl(self, self.connection)
389 else:
--> 390 sql, params = node.as_sql(self, self.connection)
391 if select_format is FORCE or (select_format and not self.query.subquery):
392 return node.output_field.select_format(self, sql, params)
/usr/local/lib/python3.6/site-packages/django/db/models/sql/where.py in as_sql(self, compiler, connection)
79 for child in self.children:
80 try:
---> 81 sql, params = compiler.compile(child)
82 except EmptyResultSet:
83 empty_needed -= 1
/usr/local/lib/python3.6/site-packages/django/db/models/sql/compiler.py in compile(self, node, select_format)
388 sql, params = vendor_impl(self, self.connection)
389 else:
--> 390 sql, params = node.as_sql(self, self.connection)
391 if select_format is FORCE or (select_format and not self.query.subquery):
392 return node.output_field.select_format(self, sql, params)
/usr/local/lib/python3.6/site-packages/django/db/models/fields/related_lookups.py in as_sql(self, compiler, connection)
128 lookup_class(target.get_col(self.lhs.alias, source), val), AND)
129 return root_constraint.as_sql(compiler, connection)
--> 130 return super().as_sql(compiler, connection)
131
132
/usr/local/lib/python3.6/site-packages/django/db/models/lookups.py in as_sql(self, compiler, connection)
161 def as_sql(self, compiler, connection):
162 lhs_sql, params = self.process_lhs(compiler, connection)
--> 163 rhs_sql, rhs_params = self.process_rhs(compiler, connection)
164 params.extend(rhs_params)
165 rhs_sql = self.get_rhs_op(connection, rhs_sql)
/usr/local/lib/python3.6/site-packages/django/db/models/lookups.py in process_rhs(self, compiler, connection)
258 'one result using slicing.'
259 )
--> 260 return super().process_rhs(compiler, connection)
261
262
/usr/local/lib/python3.6/site-packages/django/db/models/lookups.py in process_rhs(self, compiler, connection)
90 value = value.resolve_expression(compiler.query)
91 if hasattr(value, 'as_sql'):
---> 92 sql, params = compiler.compile(value)
93 return '(' + sql + ')', params
94 else:
/usr/local/lib/python3.6/site-packages/django/db/models/sql/compiler.py in compile(self, node, select_format)
388 sql, params = vendor_impl(self, self.connection)
389 else:
--> 390 sql, params = node.as_sql(self, self.connection)
391 if select_format is FORCE or (select_format and not self.query.subquery):
392 return node.output_field.select_format(self, sql, params)
/usr/local/lib/python3.6/site-packages/django/db/models/expressions.py in as_sql(self, compiler, connection)
732 def as_sql(self, compiler, connection):
733 qn = compiler.quote_name_unless_alias
--> 734 return "%s.%s" % (qn(self.alias), qn(self.target.column)), []
735
736 def relabeled_clone(self, relabels):
/usr/local/lib/python3.6/site-packages/django/db/models/sql/compiler.py in quote_name_unless_alias(self, name)
379 self.quote_cache[name] = name
380 return name
--> 381 r = self.connection.ops.quote_name(name)
382 self.quote_cache[name] = r
383 return r
/usr/local/lib/python3.6/site-packages/django/db/backends/postgresql/operations.py in quote_name(self, name)
97
98 def quote_name(self, name):
---> 99 if name.startswith('"') and name.endswith('"'):
100 return name # Quoting once is enough.
101 return '"%s"' % name
AttributeError: 'NoneType' object has no attribute 'startswith'