HackMD/lib/migrations/20150702001020-update-to-0_3_1.js

'use strict'
module.exports = {
  up: function (queryInterface, Sequelize) {
    return queryInterface.addColumn('Notes', 'shortid', {
      type: Sequelize.STRING,
      defaultValue: '0000000000',
      allowNull: false
    }).then(function () {
      return queryInterface.addIndex('Notes', ['shortid'], {
        indicesType: 'UNIQUE'
      })
    }).then(function () {
      return queryInterface.addColumn('Notes', 'permission', {
        type: Sequelize.STRING,
        defaultValue: 'private',
        allowNull: false
      })
    }).then(function () {
      return queryInterface.addColumn('Notes', 'viewcount', {
        type: Sequelize.INTEGER,
        defaultValue: 0
      })
    }).catch(function (error) {
      if (error.message === "ER_DUP_FIELDNAME: Duplicate column name 'shortid'") {
        console.log('Migration has already run… ignoring.')
      } else {
        throw error
      }
    })
  },

  down: function (queryInterface, Sequelize) {
    return queryInterface.removeColumn('Notes', 'viewcount')
      .then(function () {
        return queryInterface.removeColumn('Notes', 'permission')
      })
      .then(function () {
        return queryInterface.removeIndex('Notes', ['shortid'])
      })
      .then(function () {
        return queryInterface.removeColumn('Notes', 'shortid')
      })
  }
}