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Status Submitted
Categories Database
Created by Guest
Created on Apr 6, 2021

RELATED FEEDBACK

Pass document field to $loolup.from and $lookup.as

Suppose I have collection of documents { entityId, entity }, where entity is names of other collections I would like to make aggregation with lookup and be able to pass entity value to $lookup from and as db.collection.aggregation([{ $lookup: { from: '$entity', let: { entityId: '$entityId' }, pipeline: [{ $match: { $expr: { $eq: ['$_id', '$$entityId'] } } }], as: '$entity' } }]) As of mongo v4.4.4 that seems not working.
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  • Guest
    Jun 15, 2021
    I see, thanks for explanation.
    Reply
  • Guest
    Jun 14, 2021
    (moved this request to the Database section) You are correct, this would not work, `from` and `as` only accept static strings. There are no short-term plans to support this feature, it would require a revamp of the security model and query optimization. A similar request is also tracked here https://jira.mongodb.org/browse/SERVER-22497
    Reply