Sequelize v5 & Typescript Model Loader

Question

Sequelize v5 & Typescript Model Loader

Having previous experience with Sequelize for projects (v4), I am now venturing into starting a new project using Sequelize v5 & Typescript.

I have been following Sequelize's documentation on how to define Models at: https://sequelize.org/master/manual/typescript.html#usage-of--code-sequelize-define--code-

Currently, I have successfully set up an ORM, but only when importing the actual model for use, not through importing the db from the model loader. For example:

import { User } from "../db/models/user";

When trying to access db.User after importing the db, I just get back undefined.

I am currently struggling to find a way to make the model loader work seamlessly with Sequelize V5 and Typescript.

It seems like the system is looking for .js files, which explains why it doesn't recognize the user.ts file. However, changing it to .ts gives me the following error...

... (error message)

Despite my efforts in researching online, I have yet to find a clear answer. Dealing with getting everything aligned properly has been quite a challenge. At this point, I am running migrations/seeders as js files to avoid dealing with sequelize-typescript-cli or sequelize-typescript.

src/db/models/user.ts User Model

...(user model code as shown in original text)...

src/db/models/index.ts Model Loader

...(model loader code as shown in original text)...

Additionally, the documentation at https://sequelize.org/master/manual/typescript.html#usage provides some insights on defining models in a clearer but slightly more redundant manner. My concern now is how the 'init' method is called during the initialization of Sequelize from index.js?

typescript express sequelize.js

Answer 1

Answer №1

After successful implementation, I managed to get it working without a loop in the Model Loader. I chose to overlook the define documentation, but you can find it here.

If you prefer the detailed class approach, you can refer to this link: here

In this guide, I will walk you through setting up 2 models and their associations to assist those integrating Typescript with Sequelize v5.

I WELCOME ANY FEEDBACK ON THIS METHOD.

Let's begin by creating classes for a User and associated Identities (for API access).

/src/db/models/user.ts

// Code goes here

...

/src/db/models/identity.ts

// Another piece of code

...

By declaring virtual members and functions related to Sequelize and the Database, we have set the foundation for our project. The init<model> && associate<model> functions are crucial for linking everything together.

Note: In identity.ts, the association uses UserId instead of userId due to an unexpected issue. Updating it solved the problem, though the reason behind it remains unclear.

Next, let's put everything together

/src/db/index.ts

// More code

...

The conventional model loading process has been simplified by importing all models into Sequelize manually. Using the define method in the model classes would cause issues as non-Typescript versions only search for *.js files. Despite potential complications when transpiling to JS, this manual approach is currently adequate.

Initialization of models in Sequelize is done by calling their respective init<model> functions. Once initialized, associations are established using the associate<model> function call.

Prior to starting the express server, the index file needs to be required to kickstart the process seamlessly.

Other noteworthy aspects of my strategy: Avoiding unnecessary package installations, I opted out of sequelize-typescript and sequelize-typescript-cli. Hence, seeding and migration files were created manually without relying on a CLI tool. These files are not .ts but .js.

...

Now equipped with classes/typescript, leveraging imports to access needed models or using db.User.findAll() brings efficiency to the workflow.

Answer 2

After successful implementation, I managed to get it working without a loop in the Model Loader. I chose to overlook the define documentation, but you can find it here.

If you prefer the detailed class approach, you can refer to this link: here

In this guide, I will walk you through setting up 2 models and their associations to assist those integrating Typescript with Sequelize v5.

I WELCOME ANY FEEDBACK ON THIS METHOD.

Let's begin by creating classes for a User and associated Identities (for API access).

/src/db/models/user.ts

// Code goes here

...

/src/db/models/identity.ts

// Another piece of code

...

By declaring virtual members and functions related to Sequelize and the Database, we have set the foundation for our project. The init<model> && associate<model> functions are crucial for linking everything together.

Note: In identity.ts, the association uses UserId instead of userId due to an unexpected issue. Updating it solved the problem, though the reason behind it remains unclear.

Next, let's put everything together

/src/db/index.ts

// More code

...

The conventional model loading process has been simplified by importing all models into Sequelize manually. Using the define method in the model classes would cause issues as non-Typescript versions only search for *.js files. Despite potential complications when transpiling to JS, this manual approach is currently adequate.

Initialization of models in Sequelize is done by calling their respective init<model> functions. Once initialized, associations are established using the associate<model> function call.

Prior to starting the express server, the index file needs to be required to kickstart the process seamlessly.

Other noteworthy aspects of my strategy: Avoiding unnecessary package installations, I opted out of sequelize-typescript and sequelize-typescript-cli. Hence, seeding and migration files were created manually without relying on a CLI tool. These files are not .ts but .js.

...

Now equipped with classes/typescript, leveraging imports to access needed models or using db.User.findAll() brings efficiency to the workflow.

Sequelize v5 & Typescript Model Loader

Answer №1

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