IntelliJ IDEA Data Grip - NotSerializableException: com.oracle.truffle.api.TruffleStackTraceElement in MongoDB query

Question

I'm using a query console to make MongoDB queries.

let ids = db.collection.aggregate([
    {
        $match: { ... }
    },
    {
        $group: {
            _id: "$field"
        }
    }
]).map(doc => doc._id);

and then I want to use the variable in the 2nd query

db.collection.aggregate([
    {
        $match: {
            "field": { $in: ids },
            ...
        }
    }
]);

note: field is of a string type.

The 1st query is completed successfully, but the 2nd query fails with a strange error:

Error unmarshaling return nested exception is: WriteAbortedException writing aborted; NotSerializableException: com.oracle.truffle.api.TruffleStackTraceElement

I'm sure that something is wrong with the variable ids, cause if I amend the 2nd query with "field": { $in: ['1', '2'] }, then it works fine.

Answer 1

As it turned out, the key is to append .toArray(), so the ids variable actually becomes an array.

This works in DataGrip:

let ids = db.collection.aggregate([
    {
        $match: { ... }
    },
    {
        $group: {
            _id: "$field"
        }
    }
]).map(doc => doc._id).toArray();