ReactSensei

Add Seeder Database file for Mongo and Node

May 20, 2020

Database seeder for Node apps

  • Quick way to populate Database with data

Create a seeder file

  • $ touch seeder.js

  • fs is filesystem comes built-in to Node.js

    • We don’t have to install it
    • We need this to work with files on our machine
  • We’ll use mongoose and colors
  • We’ll need .env because we need access to the Mongo URI
  • We point to where our .env is using another built-in Node.js path
  • We point to our Model
  • We connect directly to MongoDB

seeder.js

const fs = require('fs');
const mongoose = require('mongoose');
const colors = require('colors');
const dotenv = require('dotenv');

// Load env vars
// You could put .env in root of app or put in config folder like below
dotenv.config({ path: './config/config.env' });

// Load models
// Point to where your model is location
const Bootcamp = require('./models/Bootcamp');

// Connect to Database
mongoose.connect(process.env.MONGO_URI, {
  useNewUrlParser: true,
  useCreateIndex: true,
  useFindAndModify: false,
  useUnifiedTopology: true,
});

// Read JSON files
// Pointing to where your data is stored in JSON format
const bootcamps = JSON.parse(
  fs.readFileSync(`${__dirname}/_data/bootcamps.json`, 'utf-8')
);

// Import into Database
const importData = async () => {
  try {
    await Bootcamp.create(bootcamps);

    console.log('Data Imported...'.green.inverse);
    process.exit();
  } catch (err) {
    console.error(err);
  }
};

And add a method to delete all Database

seeder.js

// MORE CODE
// Delete all data
const deleteData = async () => {
  try {
    await Bootcamp.deleteMany();

    console.log('Data Destroyed...'.red.inverse);
    process.exit();
  } catch (err) {
    console.error(err);
  }
};

Use Node argv to determine if importing or deleting data

// MORE CODE

if (process.argv[2] === '-i') {
  importData();
} else if (process.argv[2] === '-d') {
  deleteData();
}

Here is the complete file

seeder.js

const fs = require('fs');
const mongoose = require('mongoose');
const colors = require('colors');
const dotenv = require('dotenv');

// Load env vars
dotenv.config({ path: './config/config.env' });

// Load models
const Bootcamp = require('./models/Bootcamp');

// Connect to Database
mongoose.connect(process.env.MONGO_URI, {
  useNewUrlParser: true,
  useCreateIndex: true,
  useFindAndModify: false,
  useUnifiedTopology: true,
});

// Read JSON files
const bootcamps = JSON.parse(
  fs.readFileSync(`${__dirname}/_data/bootcamps.json`, 'utf-8')
);

// Import into Database
const importData = async () => {
  try {
    await Bootcamp.create(bootcamps);

    console.log('Data Imported...'.green.inverse);
    process.exit();
  } catch (err) {
    console.error(err);
  }
};

// Delete all data
const deleteData = async () => {
  try {
    await Bootcamp.deleteMany();

    console.log('Data Destroyed...'.red.inverse);
    process.exit();
  } catch (err) {
    console.error(err);
  }
};

if (process.argv[2] === '-i') {
  importData();
} else if (process.argv[2] === '-d') {
  deleteData();
}

Test it out

  • You should have an empty Database

    • If not delete all documents in your Bootcamp collection

$ node seeder -d

  • This will delete all data

Import data

$ node seeder -i

  • This will import all data from JSON file you pointed to

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