django之多数据库的处理（day-28） - 图1

    首先，在settings配置上另一个数据库running

    1. DATABASES = {
    2.     'default': {
    3.         'ENGINE': 'django.db.backends.sqlite3',
    4.         'NAME': BASE_DIR / 'db.sqlite3',
    5.     },
    6.     'running': {
    7.         'ENGINE': 'django.db.backends.mysql',
    8.         'NAME': 'running',
    9.         'USER': 'root',
    10.         'PASSWORD': '123456',
    11.         'HOST': '127.0.0.1',
    12.         'PORT': '3306',
    13.     }

    接着往项目中同步表inspectdb (‘> models.py’指定创建到根目录下的文件中，前面也可以加想要的表的名字)
    python manage.py inspectdb —database=running —settings=settings.local > models.py

    然后去创建一个APP用来存放他,记得在settings中注册running
    django-admin startapp running
    然后把刚刚的models.py的内容搬到running中去
    同时，也得在admin.py中注册models

    1. from django.contrib import admin
    3. # Register your models here.
    4. from myyuque.running.models import Country, Province
    6. admin.site.register(Country)
    7. admin.site.register(Province)

    接着重点来了！
    需要配置数据库路由，base.py同目录下创建router.py

    1. # -*- coding: utf-8 -*-
    2. from django.conf import settings
    4. DATABASE_MAPPING = settings.DATABASE_APPS_MAPPING
    7. class DatabaseAppsRouter(object):
    8.     """
    9.     A router to control all database operations on models for different
    10.     databases.
    12.     In case an app is not set in settings.DATABASE_APPS_MAPPING, the router
    13.     will fallback to the `default` database.
    15.     Settings example:
    17.     DATABASE_APPS_MAPPING = {'app1': 'db1', 'app2': 'db2'}
    18.     """
    20.     def db_for_read(self, model, **hints):
    21.         """"
    22.         Point all read operations to the specific database.
    23.         """
    24.         if model._meta.app_label in DATABASE_MAPPING:
    25.             return DATABASE_MAPPING[model._meta.app_label]
    26.         return 'default'
    28.     def db_for_write(self, model, **hints):
    29.         """
    30.         Point all write operations to the specific database.
    31.         """
    32.         if model._meta.app_label in DATABASE_MAPPING:
    33.             return DATABASE_MAPPING[model._meta.app_label]
    34.         return 'default'
    36.     def allow_relation(self, obj1, obj2, **hints):
    37.         """
    38.         Allow any relation between apps that use the same database.
    39.         """
    40.         # db_obj1 = DATABASE_MAPPING.get(obj1._meta.app_label)
    41.         # db_obj2 = DATABASE_MAPPING.get(obj2._meta.app_label)
    42.         # if db_obj1 and db_obj2:
    43.         #     if db_obj1 == db_obj2:
    44.         #         return True
    45.         #     else:
    46.         #         return False
    47.         return None
    49.     # for Django 1.4 - Django 1.6
    50.     def allow_syncdb(self, db, model):
    51.         """
    52.         Make sure that apps only appear in the related database.
    53.         """
    55.         # if db in DATABASE_MAPPING.values():
    56.         #     return DATABASE_MAPPING.get(model._meta.app_label) == db
    57.         # elif model._meta.app_label in DATABASE_MAPPING:
    58.         #     return False
    59.         return None
    61.     # Django 1.7 - Django 1.11
    62.     def allow_migrate(self, db, app_label, model_name=None, **hints):
    63.         # print db, app_label, model_name, hints
    64.         if db in DATABASE_MAPPING.values():
    65.             return DATABASE_MAPPING.get(app_label) == db
    66.         elif app_label in DATABASE_MAPPING:
    67.             return False
    68.         return None

    然后在base.py 中配置

    1. # 配置多数据库路由
    2. DATABASE_ROUTERS = ['settings.router.DatabaseAppsRouter']  # 路径
    4. # 根据app名称路由指定的数据库
    5. DATABASE_APPS_MAPPING = {   
    6.     'running': 'running',
    7. }

    最后在running的models.py中的每个Meta加上 app_label = ‘running’