How to Use Lookup in MongoDB | Join Query - Part12 of MongoDB with C# Beginner's Tutorial

This is a MongoDB C# Lookup Tutorial. Let us see how to use Lookup in MongoDB Collection from C# Application
Performs a left outer join to an unsharded collection in the same database to filter in documents from the joined collection for processing. To each input document, the lookup stage adds a new array field whose elements are the matching documents from the joined collection. The lookup stage passes these reshaped documents to the next stage.
Local Field in Lookup:
Specifies the field from the documents input to the lookup stage. Lookup performs an equality match on the local field to the foreign field from the documents of the from collection. If an input document does not contain the local field, the lookup treats the field as having a value of null for matching purposes.
Foreign Field in Lookup:
Specifies the field from the documents in the from collection. $lookup performs an equality match on the foreign field to the local field from the input documents. If a document in the from collection does not contain the foreign field, the lookup treats the value as null for matching purposes.
Playlist Link:
• MongoDB with C# Beginn...
Tutorial Video Links:
1. How to do MongoDB Basic CRUD Operations - • How to do Basic CRUD O...
2. How to do MongoDB Bulk Operations - • How to do MongoDB Bulk...
3. How to use MongoDB Filter - • How to use MongoDB Fil...
4. How to use MongoDB Upsert - • How to use MongoDB Ups...
5. More Options in MongoDB Update - • More Options in MongoD...
6. How to use MongoDB FindOneAndUpdate - • How to use MongoDB Fin...
7. How to use MongoDB BulkWrite - • How to use C# MongoDB ...
8. More Options in MongoDB Find - • More Options in MongoD...
9. How to Get Record By ID in MongoDB - • How to Get Record By I...
10. How to Create Index in MongoDB - • How to Create Index in...
11. How to use Batch Size in MongoDB Find - • How to use Batch Size ...
12. How to Use Lookup in MongoDB - • How to Use Lookup in M...
This is MongoDB and Visual Studio (C#) tutorial. All videos in this series are
developed in Visual Studio 2019 using (C#/C Sharp Language) from Microsoft. The database used is MongoDB Community Server edition.
MongoDB is a cross-platform document-oriented database program. Classified as a NoSQL database program, MongoDB uses JSON-like documents with optional schemas.

[@ologungbaradavid2181]

You have done well ....Thank you

[@CodingDroplets]

Most welcome!

[@serixg]

Thanks buddy, very clear and efficient tutorial

[@CodingDroplets]

Glad to know you liked it.

[@AbdulRasheed-m5q]

thanks.. very useful

[@CodingDroplets]

You are welcome

[@dondonherrera8141]

Hi Code Droplets, This is amazing tutorial. I’ve learned a lot. Could you please help me to do the sorting by County Name, Province Name in this code? Is it possible? Lookup and sorting at the same time from the first and second table properties? Thanks!

[@CodingDroplets]

Thank you for sharing your feedback. Happy to hear the video helped you to learn. You can do Sorting and Lookup together. Just give the Sort function immediately after the Lookup function.

[@efexzium]

Awesome videos please make a video on C# mongdb Queries

[@CodingDroplets]

There are more videos under the MongoDB Tutorial playlist. Playlist link: kzbin.info/aero/PLzewa6pjbr3JgaEaUDXWXm_bgjtQPjzFE

[@kanagavelinfotech89]

Nice video . Do you have any link from where you learned this ?

[@CodingDroplets]

I learned MongoDB C# operations from different sources. Not from a single website or video. That made us to think about creating a tutorial video series for the newcomers. Please checkout our MongoDB with C# Beginner's Tutorial (Playlist link given below) for learning more about this topic. Playlist Link: kzbin.info/aero/PLzewa6pjbr3JgaEaUDXWXm_bgjtQPjzFE