Find the most recently published post for each author

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

The compiled query

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

How the compiled query works

$sort — orders by publishedAt.
$group — groups by "$authorId" and aggregates postId.
$lookup — joins the authors collection on _id → _id.
$unwind — flattens $author into one document per element.
$lookup — joins the posts collection on postId → _id.
$unwind — flattens $post into one document per element.
$project — returns only authorName, postTitle, postPublishedAt.

Things worth knowing

Inside $group, postId takes the first value in the group — one output document per distinct "$authorId".

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Find the most recently published post for each author

The compiled query

How the compiled query works

Things worth knowing

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