Join data from collections in different databases (go griver)?

Working with Data Drivers
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2

Hey @Andrew_Rusinas , the Go Driver doesn’t have a preference for how you construct queries, the error you are getting is a response from an Atlas Server (i.e. AtlasError). The documentation you provided is specifically for querying federated data. Does running your query in mongosh result in the same error?

{
  $lookup: {
    from: {
      db: "Auth",
      coll: "user",
    },
    localField: "author_id",
    foreignField: "_id",
    as: "author",
  },
}

Here is the documentation for the from field: https://www.mongodb.com/docs/manual/reference/operator/aggregation/lookup/#std-label-lookup-eq-from:

[from] specifies the collection in the same database to perform the join with.

The Go Driver will construct the database reference from the aggregate chain:

// The database we are operating the aggregate on is "mydb", provide the 
// `from` field with the collection name.
myclient.Database("mydb").Aggregate(context.Background(), lookupPipeline)