Pymongo MongoClient：如果您通过 URI 放入数据库，您如何将其取出？

Question

The documentation for MongoClient says that one may say 'host=' and give a full MongoDB URI. Those include a database name. Once I do that, is there some way to extract the db name from the MongoClient object? I'm failing to spot it in the source code.

Answer 1

I believe what you are looking for can be found in pymongo.uri_parser . In particular, look at the parse_uri function. parse_uri takes a MongoDB URI as an argument and returns a dictionary containing values such as username , password and, most importantly, database .

Example:

from pymongo.uri_parser import parse_uri

mongo_uri = 'mongodb://james:brewer@localhost/test'

for k, v in parse_uri(mongo_uri).items():
    print k, ':', v

will print

username : james
nodelist : [('localhost', 27017)]
database : test
connection : None
password : brewer
options : {}

Hope this helps!

Answer 2

The MongoClient class has a method called get_default_database(default=None, [...other options...]) documented as:

Get the database named in the MongoDB connection URI.

MongoClient also has a method called .get_database(name=None, [... other options...]) , where the name=None parameter is defined as:

name (optional): The name of the database - a string. If None (the default) the database named in the MongoDB connection URI is returned.

So if all you have is the URI, but that URI contains a database name, You can get the MongoDB database like this:

    mongo_database = pymongo.MongoClient(host=mongo_uri).get_default_database()

Or like this:

    mongo_database = pymongo.MongoClient(host=mongo_uri).get_database()

The default= parameter in the first method above and the name= parameter in the second perform the same function: allowing the application programmer to override the database named in the URI, or supplement it if one was not provided in the URI.