@dormjs/core NPM

A light-weight ORM tool written with Typescript for Node.js based on Data Mapper pattern. Supports PostgreSQL for now.

Features (for now)

Decorators for Entities
Repository
Transactions
Custom Entity Repository
Connection pooling

Installation

Install dormjs with database driver:

npm i @dormjs/core pg

And add below to compilerOptions in tsconfig.json for decorator usages:

"experimentalDecorators": true

Usage

Dorm Initialization

Init dorm with database connection infos:

dorm.ts

const dorm = Dorm.init<PgConnector>({
  user: "postgres",
  host: "localhost",
  database: "speedy",
  password: "12345",
  port: 5432,
  connector: "pg",
  pooling: true,
})

await dorm.connect();

Entity Definition

create table book (
    id serial primary key,
    book_name text not null,
    release_date timestamp default now(),
    author_id integer not null
);

Create the entity class of the book table given above.

book.entity.ts

@model()
export class Book {
  @property({
    type: "number",
    id: true,
  })
  id?: number;

  @property({
    name: "book_name",
    type: "string",
    required: true,
  })
  name: string;

  @property({
    name: "release_date",
    type: "date",
  })
  releaseDate?: string;

  @property({
    name: "author_id",
    type: "number",
  })
  authorId: number;
}

We started class definition with @model decorator and class properties with @property decorator.

In @property decorator, we used name property for declare table real column name.

If table column name is same as class property name, no need to specify name property of @property decorator.

In @model decorator, we can specify table name if table name is different from class name.

While comparing table and class name, class name is case-insensitive.

Repository

Get repository from dorm instance and use it for all CRUD operations of all defined entities.

const repo = dorm.getRepository();

getRepository() always returns a singleton repository instance.

const book = await repo.find(Book, {
    where: {
      name: "1984",
    },
  });

Transactions

Start transactional operations with .begin(). Use returned object from function in repository's other functions as parameter.

const tx = await repo.begin();

Transaction object has two main methods:

commit
rollback

Example usage of transactions:

const tx = await repo.begin();

try {
  await repo.create(
    Book,
    { name: "Robinson Crusoe", authorId: 99 },
    { transaction: tx }
  );

  await repo.deleteById(Book, 1000, { transaction: tx });

  // write changes to db
  await tx.commit();
} catch (e) {
  // An error occured, rollback all changes!
  await tx.rollback();
}