sequelize-typescript-migration

Based on work of mandarvl at sequelize-typescript-migration.

Full credits to mmRoshani, mandarvl, kimjbstar, mricharz, syon-development, viinzzz and lou2013 for the awesome lib.

Installation

npm i @techntools/sequelize-typescript-migration

// Or

yarn add @techntools/sequelize-typescript-migration

General info

It is based on sequelize-typescript and does not support "sequelize" based model codes and you need prior knowledge of migration of Sequelize.

This scans models and its decorators to find changes, and generates migration code with this changes so don't need to write up, down function manually. This is like makemigration in django framework.

After generation is successful, you can use "migrate" in Sequelize Migration Manual

| Sometimes the undo (down) command sequence could be reordered when foreign-key chains exist. The generator produces a topological drop order (children before parents) by recording incoming references per dropped table, and applies Kahn's topological sort across all action types. If a custom migration still fails to roll back, inspect the generated down block; the actions summary in the header lists the planned order. |

Tested with

• sequelize@^6.37.7
• sequelize-typescript@^2.1.6

Usage Example

import { join } from 'path'
import { Sequelize } from "sequelize-typescript";
import { SequelizeTypescriptMigration } from "sequelize-typescript-migration-lts";

const sequelize: Sequelize = new Sequelize({
  // .. options
});

await SequelizeTypescriptMigration.makeMigration(sequelize, {
  outDir: join(__dirname, './migrations'),
  migrationName: "add-awesome-field-in-my-table",
  preview: false,
});

If you have these two models and run first makeMigration, it detects all table changes from nothing.

@Table
export class CarBrand extends Model<CarBrand> {
  @Column
  name: string;

  @Default(true)
  @Column(DataType.BOOLEAN)
  isCertified: boolean;

  @Column
  imgUrl: string;

  @Column
  orderNo: number;

  @Column
  carsCount: number;
}

@Table
export class Car extends Model<Car> {
  @Column
  name: string;

  @ForeignKey(() => CarBrand)
  @Column
  carBrandId: number;

  @BelongsTo(() => CarBrand)
  carBrand: CarBrand;
}

This will generate 00000001-noname.js in migrations path.

"use strict";

var Sequelize = require("sequelize");

/**
 * Actions summary:
 *
 * createTable "CarBrands", deps: []
 * createTable "Cars", deps: [CarBrands]
 *
 **/

var info = {
  revision: 1,
  name: "noname",
  created: "2020-04-12T15:49:58.814Z",
  comment: "",
};

var migrationCommands = [
  {
    fn: "createTable",
    params: [
      "CarBrands",
      {
        id: {
          autoIncrement: true,
          primaryKey: true,
          allowNull: false,
          type: Sequelize.INTEGER,
        },
        name: {
          type: Sequelize.STRING,
        },
        isCertified: {
          type: Sequelize.BOOLEAN,
        },
        imgUrl: {
          type: Sequelize.STRING,
        },
        orderNo: {
          type: Sequelize.INTEGER,
        },
        carsCount: {
          type: Sequelize.INTEGER,
        },
        createdAt: {
          allowNull: false,
          type: Sequelize.DATE,
        },
        updatedAt: {
          allowNull: false,
          type: Sequelize.DATE,
        },
      },
      {},
    ],
  },

  {
    fn: "createTable",
    params: [
      "Cars",
      {
        id: {
          autoIncrement: true,
          primaryKey: true,
          allowNull: false,
          type: Sequelize.INTEGER,
        },
        name: {
          type: Sequelize.STRING,
        },
        carBrandId: {
          onDelete: "NO ACTION",
          onUpdate: "CASCADE",
          references: {
            model: "CarBrands",
            key: "id",
          },
          allowNull: true,
          type: Sequelize.INTEGER,
        },
        createdAt: {
          allowNull: false,
          type: Sequelize.DATE,
        },
        updatedAt: {
          allowNull: false,
          type: Sequelize.DATE,
        },
      },
      {},
    ],
  },
];

var rollbackCommands = [
  {
    fn: "dropTable",
    params: ["Cars"],
  },
  {
    fn: "dropTable",
    params: ["CarBrands"],
  },
];

module.exports = {
  pos: 0,
  up: function (queryInterface, Sequelize) {
    var index = this.pos;
    return new Promise(function (resolve, reject) {
      function next() {
        if (index < migrationCommands.length) {
          let command = migrationCommands[index];
          console.log("[#" + index + "] execute: " + command.fn);
          index++;
          queryInterface[command.fn]
            .apply(queryInterface, command.params)
            .then(next, reject);
        } else resolve();
      }
      next();
    });
  },
  down: function (queryInterface, Sequelize) {
    var index = this.pos;
    return new Promise(function (resolve, reject) {
      function next() {
        if (index < rollbackCommands.length) {
          let command = rollbackCommands[index];
          console.log("[#" + index + "] execute: " + command.fn);
          index++;
          queryInterface[command.fn]
            .apply(queryInterface, command.params)
            .then(next, reject);
        } else resolve();
      }
      next();
    });
  },
  info: info,
};

Run npx sequelize db:migrate --to 00000001-noname.js to apply this

Possible Usage Scenario

Make sure to have writeMigration in your System under development and that sequelize is all set up.

If you change a model and re-run the backend there should be a new file under db/migrations, but the database won't update automatically. There are easy but important steps:

1. Rename the file's name as well as the content (Info: name), so that everyone knows what this migration is about
2. Migrate your database with sequelize db:migrate
3. Re-Serve the backend. You should see no changes.
4. Test the automatically created file's down function with sequelize db:migrate:undo
5. If there are any troubles, fix the auto-generated file (ordering!)
6. Run sequelize db:migrate:undo and continue your amazing work

Contributors

• Manda Ravalison
• MohammadMojtaba Roshani
• Anthony Luzquiños
• Alexandr Cherednichenko