PyMongo create unique index with 2 or more fields

问题:

How can i create index in pymongo with 2 fields, to be unique together?

I have this code:

self.db[self.mongo_collection].create_index("url", unique=True)

but i need to be unique with url and category.

回答1:

You need to create a compound index and set unique to True as mentioned in the documentation:

If you use the unique constraint on a compound index, then MongoDB will enforce uniqueness on the combination of values rather than the individual value for any or all values of the key.

self.db[self.mongo_collection].create_index(
    [("url", pymongo.DESCENDING), ("category", pymongo.ASCENDING)],
    unique=True
)