deleteMany()
deleteMany removes every document that matches the filter.
In this page:
Syntax
db.collection_name.deleteMany(filter)deleteMany()
Use deleteMany for cleanup such as removing expired sessions. An empty filter deletes all documents but leaves the collection and its indexes, unlike drop. Preview the filter with countDocuments first.
Note:
Run countDocuments with the same filter before deleting.
Example: deleteMany()
test> db.sessions.insertMany([{ _id: 1, expired: true }, { _id: 2, expired: false }, { _id: 3, expired: true }])
{ acknowledged: true, insertedIds: { '0': 1, '1': 2, '2': 3 } }
test> db.sessions.countDocuments({ expired: true })
2
test> db.sessions.deleteMany({ expired: true })
{ acknowledged: true, deletedCount: 2 }
test> db.sessions.find()
[ { _id: 2, expired: false } ]⚠️ Run this in your own terminal or Node.js environment.
Related Topics
Common Mistakes
- Passing {} by accident
- Confusing deleteMany({}) with drop
- Not testing the filter first
Chapter Summary
- deleteMany removes all matches
- {} removes everything but keeps the collection
- Preview with countDocuments
- Returns deletedCount
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