Database Models

For our TodoList application, we want to be able to store the items in our list in our database. Let's create a new model to represent the items in our list, or as TypeORM calls it, an entity.

Create a new entity

core-typeorm provides the same functionality as the TypeORM package CLI. Let's use the entity generator to create a new entity for our TodoItem.

ucore exec typeorm entity:create --name TodoItem

This will create a new file in the src/entity directory called TodoItem.ts.

npm install  @babel/plugin-proposal-decorators

{
  "plugins": [
    ["@babel/plugin-proposal-decorators", { "legacy": true }],
    "@babel/plugin-proposal-class-properties",
    "@babel/plugin-proposal-object-rest-spread"
  ]
}

{
  "compilerOptions": {
    "experimentalDecorators": true,
    "emitDecoratorMetadata": true
  }
}

This is how our TodoItem entity should look:

import {
  BaseEntity,
  Column,
  Entity,
  PrimaryGeneratedColumn,
  CreateDateColumn,
  UpdateDateColumn,
} from "typeorm";

@Entity()
export class TodoItem extends BaseEntity {
  @PrimaryGeneratedColumn({ type: "bigint" })
  id;

  @Column({ type: "text" })
  content;
  @Column({ type: "boolean" })
  done;

  @CreateDateColumn()
  createdAt;
  @UpdateDateColumn()
  updatedAt;
}

import {
  BaseEntity,
  Column,
  Entity,
  PrimaryGeneratedColumn,
  CreateDateColumn,
  UpdateDateColumn,
} from "typeorm";

@Entity()
export class TodoItem extends BaseEntity {
  @PrimaryGeneratedColumn({ type: "bigint" })
  public id: bigint;

  @Column()
  public content: string;
  @Column()
  public done: boolean;

  @CreateDateColumn()
  public createdAt: Date;
  @UpdateDateColumn()
  public updatedAt: Date;
}

We have added a few columns to our entity:

• id: This is the primary key of our entity; it is a unique identifier for each item in our list.
• content: This is the text of the item in our list.
• done: This is a boolean value that represents if the item is done or not.
• createdAt: This is a timestamp that represents when the item was created.
• updatedAt: This is a timestamp that represents when the item was last updated.

We have also extended our entity from BaseEntity, which will give us access to some helper methods that we can use to interact with our database.

Core console

universal-core provides a way for you to test code without having to write a test file or print statements. Let's enter the universal-core console and test our new entity.

ucore console

Once inside the console, we can import our entity and create a new instance of it. You can now write any JavaScript code you want to test.

const { TodoItem } = require("./src/entity/TodoItem");

Let's create an entry for our entity by instantiating it, setting the content and done properties, and saving it to the database.

const todoItem = new TodoItem();

todoItem.content = "Buy milk";
todoItem.done = false;

await todoItem.save();

You can now query the database to see if the item was saved.

await TodoItem.find();

Check out the TypeORM documentation for more information about entities and how to interact with them.