多数据库

系统应用要用到一下这些表

auth_group

auth_group_permissions

auth_permission

auth_user

auth_user_groups

auth_user_user_permissions

django_admin_log

django_content_type

django_migrations

django_session

sqlite_master

sqlite_sequence

如果需要集成现有的数据库的数据，则需要为 Django 配置多数据库

配置数据库连接

先在 settings.py 配置数据库名及其连接参数

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.sqlite3',
        'NAME': os.path.join(BASE_DIR, 'db.sqlite3'),
    },
    'cip': {
        'ENGINE': 'django.db.backends.oracle',
        'NAME': 'testdba',
        'USER': 'cipserver',
        'PASSWORD': 'neu0821',
        'HOST': '10.211.95.153',
        'PORT': '1521',
    }
}

然后就可以把该数据里的某个表导出成 model

python manage.py inspectdb --database cip cip_content_info_t > new_models.py

删除不要的属性，以及调整模型的字段数据类型，无法正确转换的都统一转换成了 TextField

class CipContentInfoT(models.Model):
    content_id = models.TextField(blank=True, null=True)  # This field type is a guess.
    content_name = models.TextField(blank=True, null=True)  # This field type is a guess.
    is_finish = models.TextField(blank=True, null=True)  # This field type is a guess.
    chapter_count = models.TextField(blank=True, null=True)  # This field type is a guess.
    content_score = models.TextField(blank=True, null=True)  # This field type is a guess.
    keywords = models.TextField(blank=True, null=True)  # This field type is a guess.
    infofee_chapter_id = models.BigIntegerField(blank=True, null=True)
    
    class Meta:
        managed = False
        db_table = 'cip_content_info_t'
        # 加上 app_label，待会实现路由逻辑的时候要用到
        app_label = 'xima'

创建一个应用，把这个模型放到应用的 models.py 模块里

python manager.py startapp xima

注册应用到 Django 系统

settings.py

INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'xima.apps.XimaConfig'
]

在 admin 里也注册，使得可以通过 admin 管理这个模型的数据

# Register your models here.
from django.contrib import admin

from .models import CipContentInfoT

admin.site.register(CipContentInfoT)

settings.py 里配置 DATABASE_ROUTERS 变量，指定一个能实现路由功能的类

DATABASE_ROUTERS = ['cip_ops.database_router.DatabaseAppsRouter']

在 Django 项目目录里创建 database_router.py 模块来实现 DatabaseAppsRouter 类

from django.conf import settings

DATABASE_MAPPING = settings.DATABASE_APPS_MAPPING


class DatabaseAppsRouter(object):
    """
    A router to control all database operations on models for different
    databases.

    In case an app is not set in settings.DATABASE_APPS_MAPPING, the router
    will fallback to the `default` database.

    Settings example:

    DATABASE_APPS_MAPPING = {'app1': 'db1', 'app2': 'db2'}
    """
    
    def db_for_read(self, model, **hints):
        """"Point all read operations to the specific database."""
        if model._meta.app_label in DATABASE_MAPPING:
            return DATABASE_MAPPING[model._meta.app_label]
        return None

    def db_for_write(self, model, **hints):
        """Point all write operations to the specific database."""
        if model._meta.app_label in DATABASE_MAPPING:
            return DATABASE_MAPPING[model._meta.app_label]
        return None

    def allow_relation(self, obj1, obj2, **hints):
        """Allow any relation between apps that use the same database."""
        db_obj1 = DATABASE_MAPPING.get(obj1._meta.app_label)
        db_obj2 = DATABASE_MAPPING.get(obj2._meta.app_label)
        if db_obj1 and db_obj2:
            if db_obj1 == db_obj2:
                return True
            else:
                return False
        return None

    def allow_syncdb(self, db, model):
        """Make sure that apps only appear in the related database."""

        if db in DATABASE_MAPPING.values():
            return DATABASE_MAPPING.get(model._meta.app_label) == db
        elif model._meta.app_label in DATABASE_MAPPING:
            return False
        return None

    def allow_migrate(self, db, app_label, model=None, **hints):
        """
        Make sure the auth app only appears in the 'auth_db'
        database.
        """
        if db in DATABASE_MAPPING.values():
            return DATABASE_MAPPING.get(app_label) == db
        elif app_label in DATABASE_MAPPING:
            return False
        return None