lb4db2app

A small LoopBack 4 app using loopback-connector-db2 connector to access a DB2 database

Set up

Update datasource config JSON

Update the values in src/datasources/db-2-ds.datasource.config.json so that you can successfully connect to your DB2 database.

{
  "name": "db2ds",
  "connector": "db2",
  "host": "the ip address",
  "port": 50000,
  "user": "db2inst1",
  "password": "your password",
  "database": "testdb",
  "schema": "db2inst1"
}

Look at the model and property settings

Open the src/models/pet.model.ts file and look at the model and property settings with regards to db2. DB2 needs to have uppercase table and columnName values. See Data Mapping Properties

import {Entity, model, property} from '@loopback/repository';

@model(
  {
    settings: {
      db2: { table: 'PET'},
    },
  }
)
export class Pet extends Entity {
  @property({
    type: 'number',
    id: true,
    generated: true,
    db2: {
      columnName: "ID"
    },
  })
  id?: number;

  @property({
    type: 'string',
    required: true,
    db2: {
      columnName: "NAME"
    },
  })
  name: string;

  @property({
    type: 'string',
    required: true,
    db2: {
      columnName: "KIND"
    },
  })
  kind: string;


  constructor(data?: Partial<Pet>) {
    super(data);
  }
}

export interface PetRelations {
  // describe navigational properties here
}

export type PetWithRelations = Pet & PetRelations;

Running the application

If the table does NOT exist in the database yet, you must run

npm run migrate

to create the table in the database. You only need to do this once.

See Database Migrations

To run the application

npm start

You will see:

Server is running at http://[::1]:3000
Try http://[::1]:3000/ping

Open your browser to : http://[::1]:3000
Click on API Explorer
Play with the REST API

Discovering models from existing database

Instead of creating models by hand, and then having the tables automatically created by LoopBack 4, you can also discover models from existing database tables using the lb4 discover command. Please see Discovering models from relational databases for details.

emonddr / lb4db2app