The $lookup Stage - MongoDB Aggregation Framework

Link to this course:
The $lookup Stage - MongoDB Aggregation Framework

This course will teach you how to perform data analysis using MongoDB's powerful Aggregation Framework.

You'll begin this course by building a foundation of essential aggregation knowledge. By understanding these features of the Aggregation Framework you will learn how to ask complex questions of your data. This will lay the groundwork for the remainder of the course where you'll dive deep and learn about schema design, relational data migrations, and machine learning with
MongoDB.

By the end of this course you'll understand how to best use MongoDB and its Aggregation Framework in your own data science workflow.

Very clear introduction to the MongoDB Aggregation Framework. Interesting and comprehensive data analysis examples as well!,Great course! It covers the essential and advanced uses of MongoDB. I highly recommend it.

The $lookup Stage - MongoDB Aggregation Framework
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[yeseulkang]

This really helped me. I think the visualization is great idea to explain complex idea like this $lookup!

[mr]

Really succinct, to-the-point tutorial!

[irhamsahbana]

Its good video, help me a lot, thanks!

[abdellatifsraiti]

you're a scholar
thank you sir

[giorgiobrugnone]

Great video tnx.
Is it possible to query results by lookup field?
In your example is it possible to get all and only Air Alliances from Canada?
Thank you for reply

[kasir-barati]

Hi, I have question about lookup, Is it looking up for every documents? I mean if in the airlines collection we had multiple documents with { name: "Delta Air Lines", /* ... */ } is it compare them multiple times (as many documents we have in airlines) with the air_alliances collection?

As i heard from a C# developer, in SQL world they have this problem, Therefore programmer/developer fetch the record (from air_alliances) in code and then simply do the same thing that database want to do for him/her.

Is it a problem or performance issue?