knex-runner v1.0.1

knex-runner

Tiny library for building a knex schema and running migrations

Knex commands run asynchronously, so you must write some boilerplate code to ensure that all of your tables are created in the correct order. This library is that boilerplate code.

Installation

$ npm install knex-runner

Usage

  var runner = require('knex-runner.js');

  runner({
    client: 'postgres',
      connection: MY_DATABASE_URL,
      migrations: {
        directory: 'my/database/migrations/path'
      }
    }, 
    schema
  );

This builds your schema, in order, and then runs any pending migrations.

schema must be an array of knex database command functions, like so:

  var createOrdersTable = function () {
    return knex.schema.hasTable('orders')
    .then(function (exists) {
      if (!exists) {
        return knex.schema.createTable('orders', function (order) {
          order.increments();
          order.string('product_name', 255);
        })
        .then(function (table) {
          console.log('created orders table');
        })
        .catch(function (err) {
          console.error('orders error: ',err);
        });
      } else {
        return new Promise(function (res, rej) {
          res();
        });
      }
    });
  };

  var createUsersTable = function () {
    return knex.schema.hasTable('users')
    .then(function (exists) {
      if (!exists) {
        return knex.schema.createTable('users', function (user) {
          user.increments();
          user.string('username', 255).index().unique();
          user.integer('last_order_id').unsigned().references('id').inTable('orders').index();
        })
        .then(function (table) {
          console.log('created users table');
        })
        .catch(function (error) {
          console.error('users error: ',error);
        });
      } else {
        return new Promise(function (res, rej) {
          res();
        });
      }
    });
  };

  var schema = [createOrdersTable, createUsersTable];

Important: as illustrated above, your commands must resolve a promise at some point. Manufacture a promise and resolve it if your function does not need to perform any knex operations under certain circumstances.

Parameters

knexOptions: knex database connection and configuration object

schema: array of knex database command functions

callback: (optional) function that should accept an error argument that will be invoked once the schema/migrations are fully run

log: (optional, defaults to true) log events to the console