Sequelize.js: Using the Model.build method will create a new empty object

Question

Sequelize.js: Using the Model.build method will create a new empty object

I am currently working with Sequelize.js (version 4.38.0) in conjunction with Typescript (version 3.0.3). Additionally, I have installed the package @types/sequelize at version 4.27.25.

The issue I am facing involves the inability to transpile the following code:

import Sequelize from 'sequelize'

const sequelize = new Sequelize('...');
const model = sequelize.define('Model', {a: Sequelize.INTEGER, b: Sequelize.INTEGER});

var instance = model.build({a: 1, b:1});
instance.save();

Upon compilation using tsc, the error message received states:

 Property 'save' does not exist on type '{}'.

It seems that the build method is returning an empty object for some reason. Attempting to use create instead results in the same error: a Promise is returned which resolves to an empty object.

Any insights or thoughts on this issue would be greatly appreciated.

typescript sequelize.js

Answer 1

Answer №1

It is crucial to explicitly declare the generic type parameters in this scenario. The definitions do not automatically deduce the types for the attributes or instance type.

import Sequelize, { Instance } from 'sequelize'

const sequelize = new Sequelize('...');

interface Model {
    x: number;
    y: string;
}


const model = sequelize.define<Instance<Model>, Model>('Model', {x: Sequelize.INTEGER, y: Sequelize.STRING});

var item = model.build({x: 2, y:'2'}); // y must be a string, preventing errors detected by TypeScript 
item.save() // all clear now

Answer 2

It is crucial to explicitly declare the generic type parameters in this scenario. The definitions do not automatically deduce the types for the attributes or instance type.

import Sequelize, { Instance } from 'sequelize'

const sequelize = new Sequelize('...');

interface Model {
    x: number;
    y: string;
}


const model = sequelize.define<Instance<Model>, Model>('Model', {x: Sequelize.INTEGER, y: Sequelize.STRING});

var item = model.build({x: 2, y:'2'}); // y must be a string, preventing errors detected by TypeScript 
item.save() // all clear now

Sequelize.js: Using the Model.build method will create a new empty object

Answer №1

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