Mongoose Many-to-Many related models with NodeJS/Express, MongoDB


In the tutorial, we will show you how to develop Mongoose Many-to-Many related documents with NodeJs/Express, MongoDB.

Related post:
Crud RestAPIs with NodeJS/Express, MongoDB using Mongoose
NodeJs/Express MongoDB One-to-Many related documents



Crud RestAPIs with NodeJS/Express, MongoDB using Mongoose
In the above tutorial, we show how to build CRUD RestAPIs with NodeJS/Express and MongoDB using Mongoose:


In the tutorial, we show how to develop Mongoose Many-to-Many related documents with NodeJS/Express, MongoDB. Project structure:

Many-to-Many related models

For working with related documents, we use the ObjectId schema field.

-> SubjectSchema:

-> StudentSchema:

We can save all references to the related documents by assigning the _id value:

We use populate() to get the Subject information in Student:

We didn’t add our students to subjects, how to get all students that learnt the same particular subject?

-> One way, we create a references array field of students in SubjectSchema as below:

But What is problem with above way? -> We have two places where the information relating students and subjects needs to be maintained.

What is the better solution?

-> We get the _id of our subject, then use find() to search for this in the subjects field across all students.


Create a NodeJS/Express project

Following below guide: Crud RestAPIs with NodeJS/Express, MongoDB using Mongoose

See dependencies in ‘package.json’ file:

Create Model Schemas

Subject Schema

Student Schema


Init Data Route

Subject Routes

Student Routes


Init Data Controller

Subject Controller

Student Controller

Run & Check results

Run MongDB server by commandline:

Run NodeJS/Express application:

– Initial data
-> http://localhost:8081/api/init


– Get All Subjects
-> http://localhost:8081/api/subjects


– Get All Students
-> http://localhost:8081/api/students


– Find Student by Name
-> http://localhost:8081/api/students/Peter

– Find Students learnt a given subject Id
-> http://localhost:8081/api/students/subject/5ad006faa6996d2634ff65f5




By grokonez | April 13, 2018.

Last updated on September 28, 2018.

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1 thought on “Mongoose Many-to-Many related models with NodeJS/Express, MongoDB”

  1. Great article but I would like to know, how one can do this with the data coming from a form rather than the hard coded data used in this example?

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