Django项目配置连接多个数据库的方法记录

Author.objects.using(\'db02\').all()

# settings.py
 
DATABASES = {
  \'default\': {
   \'ENGINE\': \'django.db.backends.oracle\',
     \'NAME\': \'orcl19c\', 
     \'USER\': \"username01\",
     \'PASSWORD\': \"password01\",
     \'HOST\': \"110.10.1.11\",
     \'PORT\': 1511,
 },
  \'db_2\': {
   \'ENGINE\': \'django.db.backends.oracle\',
     \'NAME\': \'orcl19c\', 
     \'USER\': \"username02\",
     \'PASSWORD\': \"password02\",
     \'HOST\': \"120.20.2.22\",
     \'PORT\': 1512,
 }
}
# 以下MyProject改成项目名，默认default不用修改
DATABASE_ROUTERS = [\'MyProject.database_router.DatabaseAppsRouter\']
DATABASE_APPS_MAPPING = {
    \'app01\': \'default\',
    \'app02\': \'db_2\',
}

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

python manage.py inspectdb --database db1 TableName1 > app01/models.py
 
python manage.py inspectdb --database db2 TableName2 > app02/models.py

# 编辑app01下的models.py:
class Names(models.Model): #该model使用default数据库
    id=models.CharField(primary_key=True,max_length=100, blank=True, null=True)
    name=models.CharField(max_length=32,primary_key=True,unique=True)
    
    class Meta:
        #app_label = \'app01\' #由于该model连接default数据库，所以在此无需指定
        db_table = \'names\'
        
# 编辑app02下的models.py:
class Classnum(models.Model): #该model使用default数据库
    id=models.CharField(primary_key=True,max_length=100, blank=True, null=True)
    classnum=models.CharField(max_length=32,primary_key=True,unique=True)
    
    class Meta:
        app_label = \'app02\'
        db_table = \'classnum\'

# 同步default节点数据库，只运行不带 --database参数的命令，不对其他数据库进行同步
 
python manage.py makemigrations
 
python manage.py migrate
 
# 同步db02节点数据库：
 
python manage.py makemigrations
 
python manage.py migrate --database=db02

Author.objects.using(\'other\').all()
my_object.save(using=\'legacy_users\')
my_object.delete(using=\'legacy_users\')

>>> p = Person(name=\'Fred\')
>>> p.save(using=\'first\')
>>> p.pk = None # Clear the primary key.
>>> p.save(using=\'second\') # Write a