I have a mongodb database with version 3.6.3. I have another mongodb database (on another machine) using version 4.4.5 with no documents in it. I want to put the data from the v3.6.3 into the v4.4.5 database. Can I safetly do this using mongoexport and then mongoimport or do I need to perform more steps?
Yes, mongoexport writes the documents out to a JSON file, and mongoimport can read that file and insert the documents to the new database.
These will transfer only the documents, but not index information. You many want to consider mongodump/mongorestore if you also need to move indexes.
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My application is using RethinkDb. Everything is running fine, but a new required needs to migrate the db into MongoDb.
Is this possible? How do I migrate the tables/collections, data, indexes, etc?
How about blob types, auto increments. ids?
Thanks!
Is this possible? How do I migrate the tables/collections, data, indexes, etc?
One way to migrate data from RethinkDB to MongoDB is to export data from RethinkDB using rethinkdb dump command, and then use mongoimport to import into MongoDB. For example:
rethinkdb dump -e dbname.tableName
This would generate an archive file:
rethinkdb_dump_<datetime>.tar.gz
After uncompressing the archive file, you can then use mongoimport as below:
mongoimport --jsonArray --db dbName --collection tableName ./rethinkdb_dump_<datetime>/dbName/tableName.json
Unfortunately for the indexes, the format between RethinkDB and MongoDB is quite different. The indexes are stored within the same archived file:
./rethinkdb_dump_<datetime>/dbName/tableName.info
Although you can still write a Python script to read the info file, and use MongoDB Python driver (PyMongo) to create the indexes in MongoDB. See also create_indexes() method for more information.
One of the reasons in suggesting to use Python, is because RethinkDB also has a Client Python driver. So technically, you can also skip the export stage and write a script to connect your RethinkDB to MongoDB.
Hello I have an ubuntu 14.04 server that is running mongodb 2.4.14. I need to move the mongo instance to a new server. I have installed mongo 3.4.2 on the new server and need to move the databases over. I am pretty new with mongo. I have 2 databases that are pretty big but when I do a mongo dump the file is nowhere near the site of the databases that mongo is showing.I cannot figure out how to get mongoexport to work. What would be the best way to move those databases? If possible can we just export the data from mongo and then import it?
You'll need to give more information on your issue with mongodump and what mongodump parameters you were using.
Since you are doing a migration, you'll want to use mongodump and not mongoexport. mongoexport only outputs a JSON/CSV format of a collection. Because of this, mongoexport cannot retain certain datatypes that exist in BSON and thus MongoDB does not suggest that anyone uses mongoexport for full backups; this consideration is listed on mongo's site.
mongodump will be able to accurately create a backup of your database/collection that mongorestore will be able to restore that dump to your new server.
If you haven't already, check out Back Up and Restore with MongoDB Tools
I am trying to import/restore a single collection from within MongoDB (i.e. mongorestore cannot be accessed, I think ...?).
Is it possible? What is the command? Ideally, I'd like to include indexes as well. The backup has been produced by mongodump.
Specifically, I am using the IntelliShell from the excellent MongoChef. I perform other commands in this as well, such as renaming existing collections first.
This query is related to building a small MongoDB test database from a large existing database.
My plan to execute this is as follows:
a) Use mongodump with an aggregate query which specifies my conditions for the records to be copied over to the test database.
Will this idea work? From what I have read on forums, using a MongoDB query as is in a mongodump command will not work.
Any guidance on this is most appreciated.
You can use the following command to get the subset of the DB.
mongodump --query "your query here"
For more information read the mongodump documentation here.
I am using MongoDB version 1.6.5
One of my collection has 973525 records.
when I try to export this collection mongodb exports only 101 records.
I can't figure out the problem .
any one knows the solution for it.
This sounds like corruption. If your server has not shutdown cleanly that could be the cause. Have you had system crashes where you didn't do a repair?
You can try to do a dump with mongodump --dbpath if you shut down the server first.
Note: MongoExport/Import will not be able to restore all the data since json can't represent all possible data types.