django : loading fixtures with natural foreignkey fails with 'ValueError: invalid literal for int() with base 10'
django : loading fixtures with natural foreignkey fails with 'ValueError: invalid literal for int() with base 10'
我的模特是...
class StateManager(models.Manager):
def get_by_natural_key(self, name):
return self.get(name=name)
class DistrictManager(models.Manager):
def get_by_natural_key(self, name, state):
return self.get(name=name, state=state)
class State(models.Model):
class Meta:
verbose_name = "State"
verbose_name_plural = "States"
permissions = (
('access_state', 'Can access States'),
)
COUNTRIES = (
('India', 'India'),
('USA', 'USA'),
('Thailand', 'Thailand'),
)
# Managers
objects = StateManager()
# Database fields
name = models.CharField(
'Name',
max_length=100,
unique=True,
help_text='''
100 chars max
'''
)
code = models.CharField(
'Code',
max_length=10,
unique=True,
help_text='''
10 chars max
''',
null=True, blank=True
)
country = models.CharField(
max_length=50,
default="India",
choices=COUNTRIES,
blank=False,
null=False
)
def __str__(self):
return self.name
def natural_key(self):
return (self.name,)
class District(models.Model):
class Meta:
verbose_name = "District"
verbose_name_plural = "Districts"
unique_together = (
(
"state",
"name"
),
)
# Managers
objects = DistrictManager()
# Database fields
name = models.CharField(
'Name',
max_length=100,
help_text='''
100 chars max
'''
)
code = models.CharField(
'Code',
max_length=10,
help_text='''
10 chars max
''',
null=True, blank=True
)
state = models.ForeignKey(State)
def __str__(self):
return self.name
def natural_key(self):
return (self.name,) + self.state.natural_key()
natural_key.dependencies = ['parties.state']
我的 District 模型夹具是 ....
[
{
"model": "parties.district",
"fields": {
"name": "North Andaman",
"state": [
"Andaman and Nicobar"
],
"code": "NA"
}
},
{
"model": "parties.district",
"fields": {
"name": "South Andaman",
"state": [
"Andaman and Nicobar"
],
"code": "SA"
}
}
]
其实fixture是django的'dumpdata'自己生成的
但是，在尝试加载夹具时，出现以下错误...
ValueError: invalid literal for int() with base 10: 'Andaman and Nicobar'
The full trace is given below ...
Traceback (most recent call last):
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/core/serializers/json.py", line 79, in Deserializer
for obj in PythonDeserializer(objects, **options):
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/core/serializers/python.py", line 157, in Deserializer
obj = base.build_instance(Model, data, db)
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/core/serializers/base.py", line 195, in build_instance
obj.pk = Model._default_manager.db_manager(db).get_by_natural_key(*natural_key).pk
File "/home/parijath/Projects/django_projects/webportal18_multipleapps/parties/models.py", line 17, in get_by_natural_key
return self.get(name=name, state=state)
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/db/models/manager.py", line 127, in manager_method
return getattr(self.get_queryset(), name)(*args, **kwargs)
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/db/models/query.py", line 325, in get
clone = self.filter(*args, **kwargs)
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/db/models/query.py", line 679, in filter
return self._filter_or_exclude(False, *args, **kwargs)
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/db/models/query.py", line 697, in _filter_or_exclude
clone.query.add_q(Q(*args, **kwargs))
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/db/models/sql/query.py", line 1310, in add_q
clause, require_inner = self._add_q(where_part, self.used_aliases)
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/db/models/sql/query.py", line 1338, in _add_q
allow_joins=allow_joins, split_subq=split_subq,
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/db/models/sql/query.py", line 1200, in build_filter
lookups, value)
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/db/models/fields/related.py", line 1761, in get_lookup_constraint
lookup_class(target.get_col(alias, source), val), AND)
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/db/models/lookups.py", line 101, in __init__
self.rhs = self.get_prep_lookup()
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/db/models/lookups.py", line 139, in get_prep_lookup
return self.lhs.output_field.get_prep_lookup(self.lookup_name, self.rhs)
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/db/models/fields/__init__.py", line 727, in get_prep_lookup
return self.get_prep_value(value)
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/db/models/fields/__init__.py", line 985, in get_prep_value
return int(value)
ValueError: invalid literal for int() with base 10: 'Andaman and Nicobar'
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "manage.py", line 10, in <module>
execute_from_command_line(sys.argv)
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/core/management/__init__.py", line 354, in execute_from_command_line
utility.execute()
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/core/management/__init__.py", line 346, in execute
self.fetch_command(subcommand).run_from_argv(self.argv)
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/core/management/base.py", line 394, in run_from_argv
self.execute(*args, **cmd_options)
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/core/management/base.py", line 445, in execute
output = self.handle(*args, **options)
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/core/management/commands/loaddata.py", line 60, in handle
self.loaddata(fixture_labels)
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/core/management/commands/loaddata.py", line 100, in loaddata
self.load_label(fixture_label)
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/core/management/commands/loaddata.py", line 151, in load_label
for obj in objects:
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/core/serializers/json.py", line 85, in Deserializer
six.reraise(DeserializationError, DeserializationError(e), sys.exc_info()[2])
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/utils/six.py", line 685, in reraise
raise value.with_traceback(tb)
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/core/serializers/json.py", line 79, in Deserializer
for obj in PythonDeserializer(objects, **options):
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/core/serializers/python.py", line 157, in Deserializer
obj = base.build_instance(Model, data, db)
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/core/serializers/base.py", line 195, in build_instance
obj.pk = Model._default_manager.db_manager(db).get_by_natural_key(*natural_key).pk
File "/home/parijath/Projects/django_projects/webportal18_multipleapps/parties/models.py", line 17, in get_by_natural_key
return self.get(name=name, state=state)
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/db/models/manager.py", line 127, in manager_method
return getattr(self.get_queryset(), name)(*args, **kwargs)
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/db/models/query.py", line 325, in get
clone = self.filter(*args, **kwargs)
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/db/models/query.py", line 679, in filter
return self._filter_or_exclude(False, *args, **kwargs)
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/db/models/query.py", line 697, in _filter_or_exclude
clone.query.add_q(Q(*args, **kwargs))
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/db/models/sql/query.py", line 1310, in add_q
clause, require_inner = self._add_q(where_part, self.used_aliases)
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/db/models/sql/query.py", line 1338, in _add_q
allow_joins=allow_joins, split_subq=split_subq,
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/db/models/sql/query.py", line 1200, in build_filter
lookups, value)
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/db/models/fields/related.py", line 1761, in get_lookup_constraint
lookup_class(target.get_col(alias, source), val), AND)
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/db/models/lookups.py", line 101, in __init__
self.rhs = self.get_prep_lookup()
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/db/models/lookups.py", line 139, in get_prep_lookup
return self.lhs.output_field.get_prep_lookup(self.lookup_name, self.rhs)
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/db/models/fields/__init__.py", line 727, in get_prep_lookup
return self.get_prep_value(value)
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/db/models/fields/__init__.py", line 985, in get_prep_value
return int(value)
django.core.serializers.base.DeserializationError: Problem installing fixture '/home/parijath/Projects/django_projects/webportal18_multipleapps/parties/fixtures/districts-2.json': invalid literal for int() with base 10: 'Andaman and Nicobar'
我哪里做错了？
终于，我发现了我的错误。
而不是....
class DistrictManager(models.Manager):
def get_by_natural_key(self, name, state):
return self.get(name=name, state=state)
我已将代码修改为...
class DistrictManager(models.Manager):
def get_by_natural_key(self, name, state):
return self.get(name=name, state__name=state)
这里的重点是 state__name=state（不是 state=state），我之前错过了。
我的模特是...
class StateManager(models.Manager):
def get_by_natural_key(self, name):
return self.get(name=name)
class DistrictManager(models.Manager):
def get_by_natural_key(self, name, state):
return self.get(name=name, state=state)
class State(models.Model):
class Meta:
verbose_name = "State"
verbose_name_plural = "States"
permissions = (
('access_state', 'Can access States'),
)
COUNTRIES = (
('India', 'India'),
('USA', 'USA'),
('Thailand', 'Thailand'),
)
# Managers
objects = StateManager()
# Database fields
name = models.CharField(
'Name',
max_length=100,
unique=True,
help_text='''
100 chars max
'''
)
code = models.CharField(
'Code',
max_length=10,
unique=True,
help_text='''
10 chars max
''',
null=True, blank=True
)
country = models.CharField(
max_length=50,
default="India",
choices=COUNTRIES,
blank=False,
null=False
)
def __str__(self):
return self.name
def natural_key(self):
return (self.name,)
class District(models.Model):
class Meta:
verbose_name = "District"
verbose_name_plural = "Districts"
unique_together = (
(
"state",
"name"
),
)
# Managers
objects = DistrictManager()
# Database fields
name = models.CharField(
'Name',
max_length=100,
help_text='''
100 chars max
'''
)
code = models.CharField(
'Code',
max_length=10,
help_text='''
10 chars max
''',
null=True, blank=True
)
state = models.ForeignKey(State)
def __str__(self):
return self.name
def natural_key(self):
return (self.name,) + self.state.natural_key()
natural_key.dependencies = ['parties.state']
我的 District 模型夹具是 ....
[
{
"model": "parties.district",
"fields": {
"name": "North Andaman",
"state": [
"Andaman and Nicobar"
],
"code": "NA"
}
},
{
"model": "parties.district",
"fields": {
"name": "South Andaman",
"state": [
"Andaman and Nicobar"
],
"code": "SA"
}
}
]
其实fixture是django的'dumpdata'自己生成的
但是，在尝试加载夹具时，出现以下错误...
ValueError: invalid literal for int() with base 10: 'Andaman and Nicobar'
The full trace is given below ...
Traceback (most recent call last):
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/core/serializers/json.py", line 79, in Deserializer
for obj in PythonDeserializer(objects, **options):
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/core/serializers/python.py", line 157, in Deserializer
obj = base.build_instance(Model, data, db)
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/core/serializers/base.py", line 195, in build_instance
obj.pk = Model._default_manager.db_manager(db).get_by_natural_key(*natural_key).pk
File "/home/parijath/Projects/django_projects/webportal18_multipleapps/parties/models.py", line 17, in get_by_natural_key
return self.get(name=name, state=state)
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/db/models/manager.py", line 127, in manager_method
return getattr(self.get_queryset(), name)(*args, **kwargs)
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/db/models/query.py", line 325, in get
clone = self.filter(*args, **kwargs)
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/db/models/query.py", line 679, in filter
return self._filter_or_exclude(False, *args, **kwargs)
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/db/models/query.py", line 697, in _filter_or_exclude
clone.query.add_q(Q(*args, **kwargs))
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/db/models/sql/query.py", line 1310, in add_q
clause, require_inner = self._add_q(where_part, self.used_aliases)
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/db/models/sql/query.py", line 1338, in _add_q
allow_joins=allow_joins, split_subq=split_subq,
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/db/models/sql/query.py", line 1200, in build_filter
lookups, value)
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/db/models/fields/related.py", line 1761, in get_lookup_constraint
lookup_class(target.get_col(alias, source), val), AND)
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/db/models/lookups.py", line 101, in __init__
self.rhs = self.get_prep_lookup()
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/db/models/lookups.py", line 139, in get_prep_lookup
return self.lhs.output_field.get_prep_lookup(self.lookup_name, self.rhs)
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/db/models/fields/__init__.py", line 727, in get_prep_lookup
return self.get_prep_value(value)
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/db/models/fields/__init__.py", line 985, in get_prep_value
return int(value)
ValueError: invalid literal for int() with base 10: 'Andaman and Nicobar'
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "manage.py", line 10, in <module>
execute_from_command_line(sys.argv)
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/core/management/__init__.py", line 354, in execute_from_command_line
utility.execute()
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/core/management/__init__.py", line 346, in execute
self.fetch_command(subcommand).run_from_argv(self.argv)
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/core/management/base.py", line 394, in run_from_argv
self.execute(*args, **cmd_options)
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/core/management/base.py", line 445, in execute
output = self.handle(*args, **options)
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/core/management/commands/loaddata.py", line 60, in handle
self.loaddata(fixture_labels)
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/core/management/commands/loaddata.py", line 100, in loaddata
self.load_label(fixture_label)
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/core/management/commands/loaddata.py", line 151, in load_label
for obj in objects:
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/core/serializers/json.py", line 85, in Deserializer
six.reraise(DeserializationError, DeserializationError(e), sys.exc_info()[2])
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/utils/six.py", line 685, in reraise
raise value.with_traceback(tb)
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/core/serializers/json.py", line 79, in Deserializer
for obj in PythonDeserializer(objects, **options):
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/core/serializers/python.py", line 157, in Deserializer
obj = base.build_instance(Model, data, db)
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/core/serializers/base.py", line 195, in build_instance
obj.pk = Model._default_manager.db_manager(db).get_by_natural_key(*natural_key).pk
File "/home/parijath/Projects/django_projects/webportal18_multipleapps/parties/models.py", line 17, in get_by_natural_key
return self.get(name=name, state=state)
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/db/models/manager.py", line 127, in manager_method
return getattr(self.get_queryset(), name)(*args, **kwargs)
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/db/models/query.py", line 325, in get
clone = self.filter(*args, **kwargs)
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/db/models/query.py", line 679, in filter
return self._filter_or_exclude(False, *args, **kwargs)
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/db/models/query.py", line 697, in _filter_or_exclude
clone.query.add_q(Q(*args, **kwargs))
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/db/models/sql/query.py", line 1310, in add_q
clause, require_inner = self._add_q(where_part, self.used_aliases)
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/db/models/sql/query.py", line 1338, in _add_q
allow_joins=allow_joins, split_subq=split_subq,
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/db/models/sql/query.py", line 1200, in build_filter
lookups, value)
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/db/models/fields/related.py", line 1761, in get_lookup_constraint
lookup_class(target.get_col(alias, source), val), AND)
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/db/models/lookups.py", line 101, in __init__
self.rhs = self.get_prep_lookup()
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/db/models/lookups.py", line 139, in get_prep_lookup
return self.lhs.output_field.get_prep_lookup(self.lookup_name, self.rhs)
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/db/models/fields/__init__.py", line 727, in get_prep_lookup
return self.get_prep_value(value)
File "/home/parijath/Projects/virtualenv/django18/lib/python3.4/site-packages/django/db/models/fields/__init__.py", line 985, in get_prep_value
return int(value)
django.core.serializers.base.DeserializationError: Problem installing fixture '/home/parijath/Projects/django_projects/webportal18_multipleapps/parties/fixtures/districts-2.json': invalid literal for int() with base 10: 'Andaman and Nicobar'
我哪里做错了？
终于，我发现了我的错误。
而不是....
class DistrictManager(models.Manager):
def get_by_natural_key(self, name, state):
return self.get(name=name, state=state)
我已将代码修改为...
class DistrictManager(models.Manager):
def get_by_natural_key(self, name, state):
return self.get(name=name, state__name=state)
这里的重点是 state__name=state（不是 state=state），我之前错过了。