top button
Flag Notify
    Connect to us
      Site Registration

Site Registration

MongoDB: How to delete all the documents from a collection ?

+2 votes
742 views
MongoDB: How to delete all the documents from a collection ?
posted Jun 23, 2015 by Vikram Singh

Share this question
Facebook Share Button Twitter Share Button LinkedIn Share Button
Do you want to delete all the documents one by one or in one shot ?
commented Jun 23, 2015 by Neeraj Mishra

1 Answer

0 votes

Single command to delete all the documents from a collection is db.collection_name.remove({}) .
I have verified this command. Please let me know If you are still facing any problem.

answer Jun 24, 2015 by Harshita
Similar Questions
+3 votes
MongoDB: How to remove documents from a collection which meet multi-key combination deletion criteria ?

Here I would like to explain my query a bit more.

I inserted multiple documents within a collection. Few documents have same set of keys and few of them have some extra key:value pairs . For example:
document 1 : key1 : "key1"
document 2: key1 : "key1", key2: "key2"
document 3: key1 : "key1", key2: "key2", key3 : "key3"
document 4: key1 : "key1", key3 : "key3"

Now I want to delete the documents which have key1 and key2.
What will be the command to do so ?

+1 vote
Large collections vs Large number of documents in a collection in MongoDB

I have a project, which has 1000 images. From each image, I get 1 million documents that I currently store in a mongoDB collection.

I have 2 alternatives,
1. Create a separate collection for each image, over multiple projects, say 10 projects, and each image(collection) would have 1 million documents that will be indexed. OR
2. Have a single collection and have 1000x1,000,000 documents in one collection, which again will be indexed.

My research and reading suggests that it is not a very good idea to create 1000 collections (for each image) and create an index for each one of 1000, and go with adding a billion documents to a single collection, to which mongoDB caters with no major issue.
My main aim is to enhance performance for reading. There would be no updates and deletes. Only reads and writes. I can afford writes to be slow, but not reads. So am I right in choosing the 2nd alternative?

Any guidance is highly appreciated.

+1 vote
get all the collection names from MongoDb server using C#

I am trying to get all the collection names from MongoDb server using C# code using db.GetCollectionNames() method.

I have 12 collections in my database, but the above method returns an empty list. I have verified that I am referring to the correct database. What am I doing wrong? Or if there is an alternate way?

...