deleteMany() — MongoDB Technical Interview Questions & Answers

Deletes every document matching a filter.

deleteMany()

  • Simple meaning: deleteMany removes every matching document.
  • How to use: db.students.deleteMany({ city: "TestCity" }).
  • deleteMany({}) deletes the whole collection’s documents — collection remains.
  • Common mistake: {} filter on production. No undo.
  • Interview tip: Many deletes. Contrast drop() which removes indexes too.

Technical Interview Tip: Never deleteMany({}) unless you mean it.

Code Examples for deleteMany()

deleteMany() — working example

db.users.deleteMany({ active: false })

deleteMany() — deleteMany removes every document that matches the filter.

How to Explain deleteMany() to an Interviewer

deleteMany({}) does what?

Deletes every document in the collection