README.md

Models

The models form the core of a Sequelize-based app - controllers, types, endpoints all blossom out of the data models. They're also a pain in the butt. They always seem to function, just never the way you want them to.

The goal here is to lay down a straightforward strategy for covering the basic use cases so they just work the first time.

A Basic Model

import { Table, Column, Model, PrimaryKey, AutoIncrement } from 'sequelize-typescript';
import { CharacterAttributes, CharacterCreationAttributes } from '../@types/character.types';

@Table({tableName: 'characters'})
class Character 
extends Model<CharacterAttributes, CharacterCreationAttributes> 
implements CharacterAttributes {
    
    @PrimaryKey
    @AutoIncrement
    @Column
    id!: number

    @Column
    name!: string

    @Column
    age!: number

}

First of all, never do those newlines for class...extends...implements. Horizontal scroll bars make for godawful code examples. You're welcome.

Second of all, always use that implements with the model attributes. This says "my model has at least the same properties as my interface." I haven't found a good way to do "my model has these and only these properties from my interface", so implements is the next best thing.

If you leave off implements, you'll get no TypeScript errors when your model is missing properties or using the wrong types. Rather unhelpful.

Now, what's happening here? We have a Character model. If you have a thing for cognitive cartography, you can mentally map model to database table. In this case our table would look like this:

id	name	age
-	-	-

@Table, @Column, @etc

Note that these decorators don't come from Sequelize, but rather from sequelize-typescript - a separate npm package. You don't have to define your model with decorators, but just do it anyway. It makes a much cleaner model file versus using Sequelize.define().

Even though it's optional, always give your table a name. If you don't, someone else will, and some people libraries can have really kooky ideas about how to name a table.

@Table({tableName: 'characters'})

Adding A Relation