sequelize

rootfs_overlay/lkmc/nodejs/sequelize.js

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+#!/usr/bin/env node
+
+// https://cirosantilli.com/sequelize
+//
+// Before running this:
+// * ensure that you can use peer authentication without password
+//   from the command line, i.e. `psql` works
+// * create the database for our test:
+//   ``
+//   createdb lkmc-nodejs
+//   ``
+
+const assert = require('assert');
+
+const { Sequelize, DataTypes } = require('sequelize');
+
+// To use the URI syntax, we need an explcit username and password.
+// But the second constructor works with peer authentication.
+// https://stackoverflow.com/questions/46207155/sequelize-and-peer-authentication-for-postgres
+//const sequelize = new Sequelize('postgres://user:password@localhost:5432/lkmc-nodejs')
+const sequelize = new Sequelize('lkmc-nodejs', undefined, undefined, {
+  host: '/var/run/postgresql',
+  dialect: 'postgres'
+});
+
+const IntegerNames = sequelize.define('IntegerNames', {
+  value: {
+    type: DataTypes.INTEGER,
+    allowNull: false
+  },
+  name: {
+    type: DataTypes.STRING,
+  },
+}, {});
+
+// OMG fuck this asynchronous bullshit:
+// https://stackoverflow.com/questions/39928452/execute-sequelize-queries-synchronously/43250120
+(async () => {
+
+// Connection sanity check.
+// https://stackoverflow.com/questions/19429152/check-mysql-connection-in-sequelize/31115934
+await sequelize.authenticate();
+
+// Create the database defined by `sequelize.define`.
+await IntegerNames.sync({force: true})
+// After this:
+//
+// psql lkmc-nodejs -c '\dt'
+//
+// gives:
+//
+//            List of relations
+//  Schema |     Name     | Type  | Owner
+// --------+--------------+-------+-------
+//  public | IntegerNames | table | ciro
+// (2 rows)
+//
+// and:
+//
+// psql lkmc-nodejs -c '\d+ "IntegerNames"'
+//
+// gives:
+//
+//   Column   |           Type           | Collation | Nullable |                  Default                   | Storage  | Stats target | Description
+// -----------+--------------------------+-----------+----------+--------------------------------------------+----------+--------------+-------------
+//  id        | integer                  |           | not null | nextval('"IntegerNames_id_seq"'::regclass) | plain    |              |
+//  value     | integer                  |           | not null |                                            | plain    |              |
+//  name      | character varying(255)   |           |          |                                            | extended |              |
+//  createdAt | timestamp with time zone |           | not null |                                            | plain    |              |
+//  updatedAt | timestamp with time zone |           | not null |                                            | plain    |              |
+// Indexes:
+//     "IntegerNames_pkey" PRIMARY KEY, btree (id)
+
+await IntegerNames.create({value: 2, name: 'two'});
+await IntegerNames.create({value: 3, name: 'three'});
+await IntegerNames.create({value: 5, name: 'five'});
+// psql lkmc-nodejs -c 'SELECT * FROM "IntegerNames";'
+//
+// gives:
+//
+//  id | value | name  |         createdAt          |         updatedAt
+// ----+-------+-------+----------------------------+----------------------------
+//   1 |     2 | two   | 2021-03-19 19:12:08.436+00 | 2021-03-19 19:12:08.436+00
+//   2 |     3 | three | 2021-03-19 19:12:08.436+00 | 2021-03-19 19:12:08.436+00
+//   3 |     5 | five  | 2021-03-19 19:12:08.437+00 | 2021-03-19 19:12:08.437+00
+// (3 rows)
+
+let integerNames = await IntegerNames.findAll({
+  where: {
+    value: 2
+  }
+});
+assert(integerNames[0].name === 'two');
+
+// Otherwise it hangs for 10 seconds, it seems that it keeps the connection alive.
+// https://stackoverflow.com/questions/28253831/recreating-database-sequelizejs-is-slow
+// https://github.com/sequelize/sequelize/issues/8468
+await sequelize.close();
+})();