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Franco Colmenarez 2021-09-15 12:30:13 -05:00
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@ -42,6 +42,7 @@ Mongo doesn't require schema or relations but if you need to, you can have them.
`Many-to-many` is also the same concept but with arrays.
The issue is that we might have to update each embedded document in case some information changes. It is better to use references in this case.
[More about relationships here](https://docs.mongodb.com/manual/applications/data-models-relationships/)
You can also have JOIN-like queries with `$lookup`, learn more [here](https://docs.mongodb.com/manual/reference/operator/aggregation/lookup/#mongodb-pipeline-pipe.-lookup)
# Projections
Sometimes we don't need the whole document, just a few data, so we can select just the data we need in the second parameter like so: