I am using mongoengine with Django and within my project need to connect to two instances of MongoDB while serving single request. It works just fine 开发者_如何学Pythonif I use:
connect("mdb1")
#do stuff with mdb1
...
connect("mdb2")
#do stuff with mdb2
but I am wondering if that's a proper way of doing it.
Multiple database support was added in MongoEngine 0.6
Demo using register_connection
.
alias_lists = ['users-books-db', 'user-db', 'book-db'] # list of aliases
dbs = ['author-book-pairs', 'users', 'books'] # list of databases
for alias, db in zip(alias_lists, dbs):
register_connection(alias, db)
class User(Document):
name = StringField()
meta = {"db_alias": "user-db"}
class Book(Document):
name = StringField()
meta = {"db_alias": "book-db"}
class AuthorBooks(Document):
author = ReferenceField(User)
book = ReferenceField(Book)
meta = {"db_alias": "users-books-db"}
@Ricardo at the official documentation theres a section explaining context management (i.e switching databases using the same document: http://docs.mongoengine.org/guide/connecting.html#switch-database).
The following code will switch the class User
, originally stored in users-db
to the new database archive-user-db
from mongoengine.context_managers import switch_db
class User(Document):
name = StringField()
meta = {"db_alias": "user-db"}
with switch_db(User, 'archive-user-db') as User:
User(name="Ross").save() # Saves the 'archive-user-db'
I think there is no a proper way to do this. The example of Matt turns obligatory use an connection by Document type. If I want to use one document with many connections the example doesn't fit.
精彩评论