该django.db.connections是包裹一个简单的DATABASES在你的设置中定义。包装器类在这里： django.db.utils＃L137-L227

from django.db import connections

# Add connection information dynamically..
connections.databases['new-alias'] = { ... }
# Ensure the remaining default connection information is defined.
# EDIT: this is actually performed for you in the wrapper class __getitem__
# method.. although it may be good to do it when being initially setup to
# prevent runtime errors later.
# connections.databases.ensure_defaults('new-alias')

# Use the new connection
conn = connections['new-alias']