了解数据库主机和端口？

Question

I'm new to programming. I was trying to set up a database (MangoDB) for school project. The tutorial says:

*The first step when working with PyMongo is to create a MongoClient to the running mongod instance. Doing so is easy:

from pymongo import MongoClient
client = MongoClient()

# The above code will connect on the default host and port. We can also specify the host and port explicitly, as follows:

client = MongoClient('localhost', 27017)

Or use the MongoDB URI format:

client = MongoClient('mongodb://localhost:27017/')

How do I understand the concept of "connecting default host and port" and what is the uri thing and why we should use it? Thank you.

Answer 1

You need to tell pymongo where is the database you want it to connect to.

Like many other ORMs/database-connectors pymongo uses a connection string. In Mongo's case it starts with mongodb:// (denoting the schema/protocol, just like http:// or ftp:// ).

Then comes the host (either a hostname or an IP), which denotes the machine/server on which the database resides, and lastly the port the server listens on.

If the database is on the same machine as the code, you should use 127.0.0.1 or localhost as the host.