insert or ignore multiple documents in mongoDB

Question

I have a collection in which all of my documents have at least these 2 fields, say name and url (where url is unique so I set up a unique index on it). Now if I try to insert a document with a duplicate url, it will give an error and halt the program. I don't want this behavior, but I need something like mysql's insert or ignore, so that mongoDB should not insert the document with duplicate url and continue with the next documents.

Is there some parameter I can pass to the insert command to achieve this behavior? I generally do a batch of inserts using pymongo as:

collection.insert(document_array)

Here collection is a collection and document_array is an array of documents.

So is there some way I can implement the insert or ignore functionality for a multiple document insert?

Answer 1

Use insert_many(), and set ordered=False.

This will ensure that all write operations are attempted, even if there are errors: http://api.mongodb.org/python/current/api/pymongo/collection.html#pymongo.collection.Collection.insert_many

Answer 2

Try this:

try:
    coll.insert(
        doc_or_docs=doc_array,
        continue_on_error=True)
except pymongo.errors.DuplicateKeyError:
    pass

The insert operation will still throw an exception if an error occurs in the insert (such as trying to insert a duplicate value for a unique index), but it will not affect the other items in the array. You can then swallow the error as shown above.