Insert Data on the Backend

Next, we’ll add some tasks on the backend so we can use them later.

import express from 'express'
import { remultExpress } from 'remult/remult-express'
import { Task } from '../shared/Task.js'
import { repo } from 'remult'

export const app = express()
export const api = remultExpress({
  entities: [Task],
  initApi: async () => {
    const taskRepo = repo(Task)
    if ((await taskRepo.count()) === 0) {
      await taskRepo.insert([
        { title: 'Clean car' },
        { title: 'Read a book' },
        { title: 'Buy groceries', completed: true },
        { title: 'Do laundry' },
        { title: 'Cook dinner', completed: true },
        { title: 'Walk the dog' },
      ])
    }
  },
})

app.use(api)

Code Explanation

• We added the initApi option to the remultExpress configuration.
• initApi is an asynchronous function that runs once when the server is loaded and the API is ready. It allows us to perform initial setup tasks for the API.
• We use the repo function to get the repository for the Task entity. The line const taskRepo = repo(Task) gets a Repository of type Task that we’ll use to perform all CRUD operations relevant to Task.
• The if ((await taskRepo.count()) === 0) check ensures that if there are no tasks in the database, we insert a few default tasks to get started.
• The taskRepo.insert([...]) operation inserts an array of tasks into the database if it’s initially empty, providing some sample data to work with.

See That It Works

Click on the Test the API button in the preview window. You should see a JSON array with the tasks we defined in the result.

Note: While Remult supports many relational and non-relational databases, in this tutorial we start by storing entity data in a backend JSON file stored in the db folder for the project. Later in this tutorial, we’ll switch to using SQLite.