mongosh: The MongoDB Shell

Get fluent in mongosh — connect, switch databases, insert and query documents, run JavaScript files, aggregate, index, and shape the shell to your taste.

mongosh is the JavaScript shell that ships with MongoDB, and it is nothing like a SQL prompt. You call methods on a `db` object, results come back as live JavaScript objects, and the same expressions you type interactively can be saved as `.js` files and run unchanged. We start from an empty prompt and build real fluency one small thing at a time: switching databases, inserting and reading documents, sorting and updating, aggregating to answer real questions, adding indexes and reading an execution plan, and finally driving the shell non-interactively and customising it. Writing a query and running it are taught as separate things, so each idea lands on its own.

What you'll build

• Connect with mongosh and move between databases
• Insert documents and read them back with find and projections
• Sort, limit, update and delete documents
• Aggregate with $group, $match, $sort and $lookup
• Add indexes and read an execution plan
• Run mongosh non-interactively and customise it with .mongoshrc.js

Contents

1. Open the shell
2. Check the server version
3. Switch to your database
4. Confirm where you are
5. List the databases
6. List the collections
7. Insert your first document
8. Write a seed file
9. Load the seed file
10. Read a collection
11. Remove the stray document
12. Filter with a query
13. Pick one, choose its fields
14. Count documents
15. Sort and limit
16. Compare with an operator
17. Update a field
18. Delete a document
19. Put it back
20. Group and sum
21. Filter, then sort the pipeline
22. Join with $lookup
23. Create a unique index
24. List the indexes
25. Read an execution plan
26. Use a JavaScript variable
27. Save a query to a file
28. Run the saved query
29. One value for a script
30. Export to CSV
31. Write a report script
32. Run the report non-interactively
33. Write a startup file
34. See it take effect