Django初学者在做官网Models说明书时遇到的问题想大家请教
问题遇到的现象和发生背景
我在学习Django，我之前没接触过数据库，现在刚刚开始学，目前再看Django说明书的Models部分，我看到的网页如下：
https://docs.djangoproject.com/en/4.0/topics/db/models/
问题相关代码，请勿粘贴截图
按照说明我在Models中加入了如下数据库
from django.db import models
class Person(models.Model):
SHIRT_SIZES = (
('S', 'Small'),
('M', 'Medium'),
('L', 'Large'),
)
name = models.CharField(max_length=60)
shirt_size = models.CharField(max_length=1, choices=SHIRT_SIZES)
在cmd中运行
py manage.py shell
from polls.models import Person
p =Person(name="Julian",shirt_size="S")
p.save()
运行结果及报错内容
可是却出现一大堆的错误
---------------------------------------------------------------------------
OperationalError Traceback (most recent call last)
~\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\backends\utils.py in _execute(self, sql, params, *ignored_wrapper_args)
83 else:
---> 84 return self.cursor.execute(sql, params)
85
~\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\backends\sqlite3\base.py in execute(self, query, params)
422 query = self.convert_query(query)
--> 423 return Database.Cursor.execute(self, query, params)
424
OperationalError: table polls_person has no column named name
The above exception was the direct cause of the following exception:
OperationalError Traceback (most recent call last)
<ipython-input-3-e403c3dbfc7c> in <module>
----> 1 p.save()
~\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\base.py in save(self, force_insert, force_update, using, update_fields)
724 update_fields = frozenset(loaded_fields)
725
--> 726 self.save_base(using=using, force_insert=force_insert,
727 force_update=force_update, update_fields=update_fields)
728 save.alters_data = True
~\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\base.py in save_base(self, raw, force_insert, force_update, using, update_fields)
761 if not raw:
762 parent_inserted = self._save_parents(cls, using, update_fields)
--> 763 updated = self._save_table(
764 raw, cls, force_insert or parent_inserted,
765 force_update, using, update_fields,
~\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\base.py in _save_table(self, raw, cls, force_insert, force_update, using, update_fields)
866
867 returning_fields = meta.db_returning_fields
--> 868 results = self._do_insert(cls._base_manager, using, fields, returning_fields, raw)
869 if results:
870 for value, field in zip(results[0], returning_fields):
~\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\base.py in _do_insert(self, manager, using, fields, returning_fields, raw)
904 return the newly created data for the model.
905 """
--> 906 return manager._insert(
907 [self], fields=fields, returning_fields=returning_fields,
908 using=using, raw=raw,
~\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\manager.py in manager_method(self, *args, **kwargs)
83 def create_method(name, method):
84 def manager_method(self, *args, **kwargs):
---> 85 return getattr(self.get_queryset(), name)(*args, **kwargs)
86 manager_method.__name__ = method.__name__
87 manager_method.__doc__ = method.__doc__
~\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\query.py in _insert(self, objs, fields, returning_fields, raw, using, ignore_conflicts)
1268 query = sql.InsertQuery(self.model, ignore_conflicts=ignore_conflicts)
1269 query.insert_values(fields, objs, raw=raw)
-> 1270 return query.get_compiler(using=using).execute_sql(returning_fields)
1271 _insert.alters_data = True
1272 _insert.queryset_only = False
~\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\sql\compiler.py in execute_sql(self, returning_fields)
1414 with self.connection.cursor() as cursor:
1415 for sql, params in self.as_sql():
-> 1416 cursor.execute(sql, params)
1417 if not self.returning_fields:
1418 return []
~\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\backends\utils.py in execute(self, sql, params)
96 def execute(self, sql, params=None):
97 with self.debug_sql(sql, params, use_last_executed_query=True):
---> 98 return super().execute(sql, params)
99
100 def executemany(self, sql, param_list):
~\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\backends\utils.py in execute(self, sql, params)
64
65 def execute(self, sql, params=None):
---> 66 return self._execute_with_wrappers(sql, params, many=False, executor=self._execute)
67
68 def executemany(self, sql, param_list):
~\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\backends\utils.py in _execute_with_wrappers(self, sql, params, many, executor)
73 for wrapper in reversed(self.db.execute_wrappers):
74 executor = functools.partial(wrapper, executor)
---> 75 return executor(sql, params, many, context)
76
77 def _execute(self, sql, params, *ignored_wrapper_args):
~\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\backends\utils.py in _execute(self, sql, params, *ignored_wrapper_args)
82 return self.cursor.execute(sql)
83 else:
---> 84 return self.cursor.execute(sql, params)
85
86 def _executemany(self, sql, param_list, *ignored_wrapper_args):
~\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\utils.py in __exit__(self, exc_type, exc_value, traceback)
88 if dj_exc_type not in (DataError, IntegrityError):
89 self.wrapper.errors_occurred = True
---> 90 raise dj_exc_value.with_traceback(traceback) from exc_value
91
92 def __call__(self, func):
~\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\backends\utils.py in _execute(self, sql, params, *ignored_wrapper_args)
82 return self.cursor.execute(sql)
83 else:
---> 84 return self.cursor.execute(sql, params)
85
86 def _executemany(self, sql, param_list, *ignored_wrapper_args):
~\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\backends\sqlite3\base.py in execute(self, query, params)
421 return Database.Cursor.execute(self, query)
422 query = self.convert_query(query)
--> 423 return Database.Cursor.execute(self, query, params)
424
425 def executemany(self, query, param_list):
OperationalError: table polls_person has no column named name
我的解答思路和尝试过的方法
我尝试过 manage.py migrate和 manage.py makemigrations，但好像都不管用。
你使用的什么数据库,mysql,还是其他,mysql先要下载pymysql,在项目settings.py统计目录下的init.py文件初始化mysql
import pymysql
pymysql.version_info = (1, 4, 6, 'final', 0) # change mysqlclient version
pymysql.install_as_MySQLdb()
将settings.py文件内的DATABASES修改成如下
DATABASES = {
'default': {
'ENGINE': 'django.db.backends.mysql',
'NAME': '你创建的数据库名',
'USER': 'root',
'PASSWORD': '你的数据库密码.',
'HOST': '192.168.2.2',
# 'HOST': '127.0.0.1',
'PORT': '3306',
'TEST': {
'NAME': 'django_db_test' # 用于单元测试的数据库
}
}
}
之后再调用
python manage.py makemigrations
python manage.py migrate
有帮助请点击一下采纳,有问题评论交流
先 python manage.py makemigrations ，再 python manage.py migrate ， 这个过程有报错吗？没报错的话，打开你的SQLite。看看表格里面有没有新建的table以及对应的title。 一步步排查
刚学的话尽量在django里调用，等熟悉了在cmd。django这边调用没问题，在用cmd
是不是忘了激活模型要先在cmd里输入
python manage.py makemigrations 应用名
再输入
python manage.py sqlmigrate 应用名 0001
再去试一遍
我我我！
可能是没更新数据库，在CMD里输入两行代码：
python manage.py makemigrations
python manage.py migrate