Small Knex.js tutorial

Initial steps

• Create the app and set stuff up.

  git init
  nvm use 6
  npm init
  npm i tape --save-dev
  npm i knex sqlite3 --save
  echo "node_modules" > .gitignore
  echo "*.sqlite" >> .gitignore
  echo "6" > .nvmrc
  git add .
  git commit -m "Initial commit"

• Add scripts in package.json to run knex.

  "scripts": {
    "init": "knex init",
    "migrate:make": "knex migrate:make",
    "migrate:latest": "knex migrate:latest",
    "migrate:rollback": "knex migrate:rollback",
    "seed:make": "knex seed:make",
    "seed:run": "knex seed:run",
    "test": "tape tests.js"
  },

• Create knexfile.js by running npm run init.

• Prune the knexfile.js to:

  module.exports = {
    development: {
      client: 'sqlite3',
      connection: {
        filename: './dev.sqlite'
      },
      useNullAsDefault: true
    }
  } 

• Create Users table by running npm run migrate:make create-users

• Edit the migration file accordingly:

  exports.up = function (knex, Promise) {
    console.log('Creating Users')
    return knex.schema.createTableIfNotExists('Users', function (table) {
      table.increments('id')
      table.string('firstName')
      table.string('lastName')
      table.string('username')
    })
  }
  
  exports.down = function (knex, Promise) {
    console.log('Dropping Users')
    return knex.schema.dropTableIfExists('Users').then(function () {
      console.log('Users table was dropped')
    })
  }

• Apply the migration file by running npm run migrate:latest.

• Open dev.sqlite in the SQLite Manager tool and verify schema.

• Create a new seed by running npm run seed:make test-users.

• Change table to Users and add some objects with firstName, lastName and username properties.

• Apply the seed data by running npm run seed:run.

• Refresh the Users table and verify the data was inserted.

• Smile 😃 nice work!

Next steps

• Drop the Users table by running npm run migrate:rollback.

• Reapply the migration to add the table back and add the test data back.

• Write some scripts that perform CRUD operations on the database. You will need to read the docs to do this because we haven't talked about how to do this yet.