Relationships

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Franco Colmenarez 2021-09-15 12:23:11 -05:00
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@ -41,6 +41,7 @@ Mongo doesn't require schema or relations but if you need to, you can have them.
`One-to-many` could be an ID that points to another ID but this is way too "SQL" style. The other approach is to have an embeded document. `One-to-many` could be an ID that points to another ID but this is way too "SQL" style. The other approach is to have an embeded document.
`Many-to-many` is also the same concept but with arrays. `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. 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/)
# Projections # 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: 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: