I have a collection of 1000 documents already having column old_col.
Now I want to add new columns in this existing document, for multiple rows at once.
For instance, the existing situation would be:
{"old_col"=1},{"old_col"=2},{"old_col"=1000}
...to be changed to:
{"old_col"=1,"new_col"=11},{"old_col"=2,"new_col"=12},{"old_col"=1000,"new_col"=11000}.
How can I do this?
Related
Say I have a MongoDB collection with 5,000 records (or thousands). I want to update this collection with new records.
These new records can be the same or with few updated records.
To do this, I have 2 approaches:
Iterate over these records and determine which ones to update (based on a condition). If the condition is truthy update the record.
Delete all the existing records (deleteMany), and then simply add new data.
Which one would be more performant and optimised? And why? Or this there another way?
I want to duplicate my all records in my collection of mongodb.
eg:
my collection have 1500 records so i need to change it into 3000.
means double
I need any query which can do this in one command
You can find everything using find then use foreach loop to insert it again.
db.col.find({},{_id:0}).forEach((doc)=>{db.col.save(doc)});
Make sure to remove _id because every duplicate is going to have its own unique _id
I am a newbie to MongoDB. I want to move 1-day data from collectionA to collection-date (this collection-date name has to create dynamically) automatically every day. The moved records should not avail in collectionA. Is this possible in mongodb?
I have Too much records in my Collection, can I have only desired number of records and remove others without any condition?
I have a collection called Products with around 10,0000 of records and its slowing down my Local application, I am thinking to shrink this huge amount of records to something around 1000, How can do it?
OR
How to copy a collection with limited number of records?
If you want to copy collection with limited number of records without any filter condition, for loop can be used . It copies 1000 document form originalCollection to copyCollection.
db.originalCollection.find().limit(1000).forEach( function(doc)
{db.copyCollection.insert(doc)} );
I have 10000 documents in one MongoDB collection. I'd like to update all the documents with datetime values that are 1 second apart for each document (so all the date time values are unique and are spaced 1 second apart). Is there any way to do this with a single update instead of updating each document in turn which results in 10000 distinct update operations?
Thanks.
No, there is no way to do this with a single update statement. There are no expressions which run at the server to allow this type of update. There is a feature request for this but it is not done so it cannot be used.