Find teams that have no users

MongoDB query compiled from plain English against the saasUsers sample schema, then verified by running it.

The compiled query

{
  "type": "aggregation",
  "collection": "teams",
  "pipeline": [
    {},
    {},
    {}
  ]
}

How the compiled query works

$lookup — joins the users collection on _id → teamId.
$match — filters on users.
$project — returns only name, plan.

Things worth knowing

This is the anti-join ("NOT EXISTS") pattern: join the related collection, then keep only the documents where nothing matched. Filtering with $ne or $exists instead is the common mistake — it does not do the same thing.

Write this in plain English instead. Mask Databases compiles the sentence above into exactly this query at build time — no AI at runtime, and you can read the output in a diff.

Try it in the playground → No signup, runs in your browser.

Find teams that have no users

The compiled query

How the compiled query works

Things worth knowing

Related queries