每个模型是一个Python 类，集成django.db.models.Modle类
该模型的每个属性表示一个数据库表字段
通过API 自动生成数据库访问 .../sign/modles.py 文件，通过模型完成表创建。
TypeError: ForeignKey.__init__() missing 1 required positional argument: 'on_delete'
E:\data\python\djaongo_prj\guest> python manage.py makeigrations sign
Traceback (most recent call last):
File "E:\data\python\djaongo_prj\guest\manage.py", line 21, in <module>
main()
File "E:\data\python\djaongo_prj\guest\manage.py", line 17, in main
execute_from_command_line(sys.argv)
File "D:\software\python3\anconda3\Lib\site-packages\django\core\management\__init__.py", line 442, in execute_from_command_line
utility.execute()
File "D:\software\python3\anconda3\Lib\site-packages\django\core\management\__init__.py", line 416, in execute
django.setup()
File "D:\software\python3\anconda3\Lib\site-packages\django\__init__.py", line 24, in setup
apps.populate(settings.INSTALLED_APPS)
File "D:\software\python3\anconda3\Lib\site-packages\django\apps\registry.py", line 116, in populate
app_config.import_models()
File "D:\software\python3\anconda3\Lib\site-packages\django\apps\config.py", line 269, in import_models
self.models_module = import_module(models_module_name)
File "D:\software\python3\python310\lib\importlib\__init__.py", line 126, in import_module
return _bootstrap._gcd_import(name[level:], package, level)
File "<frozen importlib._bootstrap>", line 1050, in _gcd_import
File "<frozen importlib._bootstrap>", line 1027, in _find_and_load
File "<frozen importlib._bootstrap>", line 1006, in _find_and_load_unlocked
File "<frozen importlib._bootstrap>", line 688, in _load_unlocked
File "<frozen importlib._bootstrap_external>", line 883, in exec_module
File "<frozen importlib._bootstrap>", line 241, in _call_with_frames_removed
File "E:\data\python\djaongo_prj\guest\sign\models.py", line 20, in <module>
class Guest(models.Model):
File "E:\data\python\djaongo_prj\guest\sign\models.py", line 21, in Guest
event = models.ForeignKey(Event) # 关联发布会id
TypeError: ForeignKey.__init__() missing 1 required positional argument: 'on_delete'必须要设置级联删除，也就是当你删除一条信息时，会级联的删除所有和这一条信息对应的另一张表的多个信息，也就是指定on_delete=models.CASCADE
event = models.ForeignKey(Event,on_delete=models.CASCADE) # 关联发布会id
# 嘉宾
class Guest(models.Model):
event = models.ForeignKey(Event,on_delete=models.CASCADE) # 关联发布会id
realname = models.CharField(max_length=64) # 姓名
phone = models.CharField(max_length=16) # 手机号
email = models.EmailField() # 邮箱
sign = models.BooleanField() # 签到状态
create_time = models.DateTimeField(auto_now=True) # 创建时间（自动获取当前时间）
class Meta:
unique_together = ('phone', 'event')
def __str__(self):
return self.realnamepython manage.py makemigrations sign
E:\data\python\djaongo_prj\guest> python manage.py makemigrations sign
System check identified some issues:
WARNINGS:
sign.Event: (models.W042) Auto-created primary key used when not defining a primary key type, by default 'django.db.models.AutoField'.
HINT: Configure the DEFAULT_AUTO_FIELD setting or the SignConfig.default_auto_field attribute to point to a subclass of AutoField, e.g. 'django.db.models.BigAutoField'.
sign.Guest: (models.W042) Auto-created primary key used when not defining a primary key type, by default 'django.db.models.AutoField'.
HINT: Configure the DEFAULT_AUTO_FIELD setting or the SignConfig.default_auto_field attribute to point to a subclass of AutoField, e.g. 'django.db.models.BigAutoField'.
Migrations for 'sign':
sign\migrations\0001_initial.py
- Create model Event
- Create model Guestpython manage.py migrate
E:\data\python\djaongo_prj\guest> python manage.py migrate
System check identified some issues:
WARNINGS:
sign.Event: (models.W042) Auto-created primary key used when not defining a primary key type, by default 'django.db.models.AutoField'.
HINT: Configure the DEFAULT_AUTO_FIELD setting or the SignConfig.default_auto_field attribute to point to a subclass of AutoField, e.g. 'django.db.models.BigAutoField'.
sign.Guest: (models.W042) Auto-created primary key used when not defining a primary key type, by default 'django.db.models.AutoField'.
HINT: Configure the DEFAULT_AUTO_FIELD setting or the SignConfig.default_auto_field attribute to point to a subclass of AutoField, e.g. 'django.db.models.BigAutoField'.
Operations to perform:
Apply all migrations: admin, auth, contenttypes, sessions, sign
Running migrations:
Applying auth.0012_alter_user_first_name_max_length... OK
Applying sign.0001_initial... OK
E:\data\python\djaongo_prj\guest>admin 后台 管理
from django.contrib import admin
# Register your models here.
# admin 后台管理 创建的发布会和嘉宾表示同样可以通过Admin 后台管理
from django.contrib import admin
from sign.models import Event ,Guest
# Register your models here.
class EventAdmin(admin.ModelAdmin):
list_display = ['name', 'status', 'start_time','id']
search_fields = ['name'] # 搜索功能
list_filter = ['status'] # 过滤器
class GuestAdmin(admin.ModelAdmin):
list_display = ['realname', 'phone','email','sign','create_time','event_id']
list_display_links = ('realname', 'phone') # 显示链接
search_fields = ['realname','phone'] # 搜索功能
list_filter = ['sign'] # 过滤器
admin.site.register(Event, EventAdmin)
admin.site.register(Guest, GuestAdmin)
Microsoft Windows [版本 10.0.19045.3448]
(c) Microsoft Corporation。保留所有权利。
E:\data\python\djaongo_prj\guest>python manage.py shell
Python 3.10.0 (tags/v3.10.0:b494f59, Oct 4 2021, 19:00:18) [MSC v.1929 64 bit (AMD64)]
Type 'copyright', 'credits' or 'license' for more information
IPython 8.10.0 -- An enhanced Interactive Python. Type '?' for help.
In [1]:
In [1]:
In [1]: from sign.models import Event,Guest
In [2]: Event.objects.all()
Out[2]: <QuerySet [<Event: 小米5发布会>]>
In [3]:
from sign.models import Event,Guest 导入模块
Event.objects.all() 所有对象
配置 MySQL
pip install pymysql
数据库创建表
报错 [Err] 1055 - Expression #1 of ORDER BY
[Err] 1055 - Expression #1 of ORDER BY clause is not in GROUP BY clause and contains nonaggregated column 'information_schema.PROFILING.SEQ' which is not functionally dependent on columns in GROUP BY clause; this is incompatible with sql_mode=only_full_group_by
在配置文件的末尾加上这段代码：
[mysqld]
sql_mode=STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_ENGINE_SUBSTITUTION
CREATE TABLE `sign_event` (
`id` int NOT NULL AUTO_INCREMENT,
`name` varchar(50) DEFAULT NULL COMMENT '名称',
`limit` int DEFAULT NULL COMMENT 'limit',
`status` varchar(1) DEFAULT '1' COMMENT '状态 0：隐藏 1：显示',
`address` varchar(500) DEFAULT NULL COMMENT '地址',
start_time DATE,
create_time DATE,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COMMENT='系统配置信息表';CREATE TABLE `sign_guest` (
`event_id` int NOT NULL ,
`realname` varchar(50) DEFAULT NULL COMMENT '名称',
`phone` varchar(11) COMMENT '手机号',
`email` varchar(50) ,
`sign` VARCHAR(1) DEFAULT '1' COMMENT '状态 0：隐藏 1：显示',
create_time DATE,
PRIMARY KEY (`event_id`,`phone`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COMMENT='嘉宾表';insert into sign_guest(realname,phone,email,sign,event_id,create_time)values("tom","12344444","[email protected]",1,123456,now())
select * from sign_guest
from pymysql import cursors, connect
# 连接数据库
conn = connect(host='192.168.56.10', user='root', password='root',
db='guest', charset='utf8mb4', cursorclass=cursors.DictCursor)
try:
with conn.cursor() as cursors:
# 创建嘉宾数据
sql = 'insert into sign_guest(realname,phone,email,sign,event_id,create_time)values("tom2","12344444","[email protected]",1,123456,now())'
cursors.execute(sql)
conn.commit()
with conn.cursor() as cursor:
# 查询
sql = "select * from sign_guest where phone=%s"
cursor.execute(sql, ('12344444',))
res = cursor.fetchone()
print(res)
finally:
conn.close() 
Django 连接 mysql
DATABASES = {
'default': {
'ENGINE': 'django.db.backends.sqlite3',
'NAME': os.path.join(BASE_DIR, 'db.sqlite3'),
}
}
import pymysql
pymysql.install_as_MySQLdb()
"""
如果你使用pymysql驱动的话，上面两行必须添加。
"""E:\data\python\djaongo_prj\guest> python manage.py migrate
Traceback (most recent call last):
File "E:\data\python\djaongo_prj\guest\manage.py", line 21, in <module>
main()
File "E:\data\python\djaongo_prj\guest\manage.py", line 17, in main
execute_from_command_line(sys.argv)
File "D:\software\python3\anconda3\Lib\site-packages\django\core\management\__init__.py", line 442, in execute_from_command_line
utility.execute()
File "D:\software\python3\anconda3\Lib\site-packages\django\core\management\__init__.py", line 436, in execute
self.fetch_command(subcommand).run_from_argv(self.argv)
File "D:\software\python3\anconda3\Lib\site-packages\django\core\management\base.py", line 412, in run_from_argv
self.execute(*args, **cmd_options)
File "D:\software\python3\anconda3\Lib\site-packages\django\core\management\base.py", line 458, in execute
output = self.handle(*args, **options)
File "D:\software\python3\anconda3\Lib\site-packages\django\core\management\base.py", line 106, in wrapper
res = handle_func(*args, **kwargs)
File "D:\software\python3\anconda3\Lib\site-packages\django\core\management\commands\migrate.py", line 100, in handle
self.check(databases=[database])
File "D:\software\python3\anconda3\Lib\site-packages\django\core\management\base.py", line 485, in check
all_issues = checks.run_checks(
File "D:\software\python3\anconda3\Lib\site-packages\django\core\checks\registry.py", line 88, in run_checks
new_errors = check(app_configs=app_configs, databases=databases)
File "D:\software\python3\anconda3\Lib\site-packages\django\core\checks\model_checks.py", line 36, in check_all_models
errors.extend(model.check(**kwargs))
File "D:\software\python3\anconda3\Lib\site-packages\django\db\models\base.py", line 1558, in check
*cls._check_indexes(databases),
File "D:\software\python3\anconda3\Lib\site-packages\django\db\models\base.py", line 2002, in _check_indexes
connection.features.supports_expression_indexes
File "D:\software\python3\anconda3\Lib\site-packages\django\utils\functional.py", line 57, in __get__
res = instance.__dict__[self.name] = self.func(instance)
File "D:\software\python3\anconda3\Lib\site-packages\django\db\backends\mysql\features.py", line 317, in supports_expression_indexes
not self.connection.mysql_is_mariadb
File "D:\software\python3\anconda3\Lib\site-packages\django\utils\functional.py", line 57, in __get__
res = instance.__dict__[self.name] = self.func(instance)
File "D:\software\python3\anconda3\Lib\site-packages\django\db\backends\mysql\base.py", line 439, in mysql_is_mariadb
return "mariadb" in self.mysql_server_info.lower()
File "D:\software\python3\anconda3\Lib\site-packages\django\utils\functional.py", line 57, in __get__
res = instance.__dict__[self.name] = self.func(instance)
File "D:\software\python3\anconda3\Lib\site-packages\django\db\backends\mysql\base.py", line 425, in mysql_server_info
return self.mysql_server_data["version"]
File "D:\software\python3\anconda3\Lib\site-packages\django\utils\functional.py", line 57, in __get__
res = instance.__dict__[self.name] = self.func(instance)
File "D:\software\python3\anconda3\Lib\site-packages\django\db\backends\mysql\base.py", line 399, in mysql_server_data
with self.temporary_connection() as cursor:
File "D:\software\python3\python310\lib\contextlib.py", line 135, in __enter__
return next(self.gen)
File "D:\software\python3\anconda3\Lib\site-packages\django\db\backends\base\base.py", line 705, in temporary_connection
with self.cursor() as cursor:
File "D:\software\python3\anconda3\Lib\site-packages\django\utils\asyncio.py", line 26, in inner
return func(*args, **kwargs)
File "D:\software\python3\anconda3\Lib\site-packages\django\db\backends\base\base.py", line 330, in cursor
return self._cursor()
File "D:\software\python3\anconda3\Lib\site-packages\django\db\backends\base\base.py", line 306, in _cursor
self.ensure_connection()
File "D:\software\python3\anconda3\Lib\site-packages\django\utils\asyncio.py", line 26, in inner
return func(*args, **kwargs)
File "D:\software\python3\anconda3\Lib\site-packages\django\db\backends\base\base.py", line 289, in ensure_connection
self.connect()
File "D:\software\python3\anconda3\Lib\site-packages\django\utils\asyncio.py", line 26, in inner
return func(*args, **kwargs)
File "D:\software\python3\anconda3\Lib\site-packages\django\db\backends\base\base.py", line 272, in connect
self.init_connection_state()
File "D:\software\python3\anconda3\Lib\site-packages\django\db\backends\mysql\base.py", line 257, in init_connection_state
super().init_connection_state()
File "D:\software\python3\anconda3\Lib\site-packages\django\db\backends\base\base.py", line 239, in init_connection_state
self.check_database_version_supported()
File "D:\software\python3\anconda3\Lib\site-packages\django\db\backends\base\base.py", line 214, in check_database_version_supported
raise NotSupportedError(
django.db.utils.NotSupportedError: MySQL 8 or later is required (found 5.7.36).
E:\data\python\djaongo_prj\guest>django.db.utils.NotSupportedError: MySQL 8 or later is required (found 5.7.36).
这个问题是说我们的Django框架版本比较新，已经不支持MySQL老版本5.7.2了，MySQL8或者更新的版本才是我们需要的或者说匹配的。
解决方案
从问题出发的解决方案有两个，①卸载老版本的MySQL，安装项目支持的新版本 ②降低Django框架的版本
pip uninstall django
pip install django==2.1.13
要重启pycharm
Error: [WinError 10013] 以一种访问权限不允许的方式做了一个访问套接字的尝试。
Django-解决报错Error: [WinError 10013] 以一种访问权限不允许的方式做了一个访问套接字的尝试。_Python454的博客-CSDN博客
E:\data\python\djaongo_prj\guest>netstat -aon|findstr "8000"
TCP 0.0.0.0:8000 0.0.0.0:0 LISTENING 14756
UDP 0.0.0.0:8000 *:*
PID =14756
任务管理器 详细信息
D:\software\python3\python310\python.exe E:/data/python/djaongo_prj/guest/manage.py runserver 127.0.0.1:8001
D:\software\python3\anconda3\Lib\site-packages\numpy\__init__.py:138: UserWarning: mkl-service package failed to import, therefore Intel(R) MKL initialization ensuring its correct out-of-the box operation under condition when Gnu OpenMP had already been loaded by Python process is not assured. Please install mkl-service package, see http://github.com/IntelPython/mkl-service
from . import _distributor_init
D:\software\python3\anconda3\Lib\site-packages\numpy\__init__.py:138: UserWarning: mkl-service package failed to import, therefore Intel(R) MKL initialization ensuring its correct out-of-the box operation under condition when Gnu OpenMP had already been loaded by Python process is not assured. Please install mkl-service package, see http://github.com/IntelPython/mkl-service
from . import _distributor_init
Performing system checks...
System check identified no issues (0 silenced).
You have 16 unapplied migration(s). Your project may not work properly until you apply the migrations for app(s): admin, auth, contenttypes, sessions, sign.
Run 'python manage.py migrate' to apply them.
October 02, 2023 - 21:57:38
Django version 2.1.13, using settings 'guest.settings'
Starting development server at http://127.0.0.1:8001/
Quit the server with CTRL-BREAK.
设置 runserver 127.0.0.1:8001
启动成功
删除 数据库中 sign_event 表
python manage.py migrate
File "D:\software\python3\anconda3\Lib\site-packages\pymysql\protocol.py", line 221, in raise_for_error
err.raise_mysql_exception(self._data)
File "D:\software\python3\anconda3\Lib\site-packages\pymysql\err.py", line 143, in raise_mysql_exception
raise errorclass(errno, errval)
django.db.utils.OperationalError: (1050, "Table 'sign_event' already exists")
E:\data\python\djaongo_prj\guest>python manage.py migrate
Operations to perform:
Apply all migrations: admin, auth, contenttypes, sessions, sign
Running migrations:
Applying sign.0001_initial... OK
E:\data\python\djaongo_prj\guest>
重新生成后台管理admin
python manage.py createsuperuser
E:\data\python\djaongo_prj\guest>python manage.py createsuperuser
Username (leave blank to use 'administrator'): admin
Email address: [email protected]
Password:
Password (again):
Superuser created successfully.