Why should you care?

TTL-style cleanup of expired sessions, purging old notifications, or wiping a test tenant’s rows uses deleteMany.

See it live — copy this example

Open mongosh or MongoDB Compass, select database nosqlverse, then run the example. Change one field and run again.

db.notifications.insertMany([
  { userId: 1, read: true, msg: "Welcome" },
  { userId: 1, read: true, msg: "Sale" },
  { userId: 1, read: false, msg: "OTP" }
])
db.notifications.deleteMany({ userId: 1, read: true })
db.notifications.find({ userId: 1 })

Run Example »

Edit the code below and click Run to see the result in Toolliyo’s live editor.

What happened?

• Both read notifications for user 1 are deleted.
• The unread OTP remains.
• find shows a single document.
• modified bulk delete is intentional here.

Practice next

1. Seed the three notifications.
2. Run deleteMany and confirm deletedCount 2.
3. Verify OTP still exists.
4. Delete only msg: /Sale/.
5. Count before and after with countDocuments.

Remember

deleteMany removes all matches. Always double-check the filter. Prefer ranged filters for cleanup jobs.

Clear read inbox older than 30 days

A nightly job deletes read notifications past a date for all users in batches.

Outcome: Storage stays flat without deleting unread OTPs.