npm package: @lorefnon/ts-pg-migrate
Description: Type-safe Postgresql database migration management tool for node.js
Author: Theo Ephraim
Latest version: 7.3.2

# @lorefnon/ts-pg-migrate

Database migration management built exclusively for postgres & Node.js. (But can also be used for other DBs conforming to SQL standard - e.g. [CockroachDB](https://github.com/cockroachdb/cockroach).)

## Installation

    $ npm install @lorefnon/ts-pg-migrate pg

Installing this module adds a runnable file into your `node_modules/.bin` directory. If installed globally (with the -g option), you can run `ts-pg-migrate` and if not, you can run `./node_modules/.bin/ts-pg-migrate`

It will also install [`pg`](https://node-postgres.com/) library as it is peer dependency used for migrations.

## Quick Example

Add `"migrate": "ts-pg-migrate"` to `scripts` section of `package.json` so you are able to quickly run commands.

Run `npm run migrate create my first migration`. It will create file `xxx_my-first-migration.js` in `migrations` folder.
Open it and change contents to:

```js
exports.up = (pgm) => {
  pgm.createTable('users', {
    id: 'id',
    name: { type: 'varchar(1000)', notNull: true },
    createdAt: {
      type: 'timestamp',
      notNull: true,
      default: pgm.func('current_timestamp'),
    },
  })
  pgm.createTable('posts', {
    id: 'id',
    userId: {
      type: 'integer',
      notNull: true,
      references: '"users"',
      onDelete: 'cascade',
    },
    body: { type: 'text', notNull: true },
    createdAt: {
      type: 'timestamp',
      notNull: true,
      default: pgm.func('current_timestamp'),
    },
  })
  pgm.createIndex('posts', 'userId')
}
```

Save migration file.

Now you should put your DB connection string to `DATABASE_URL` environment variable and run `npm run migrate up`.
(e.g. `DATABASE_URL=postgres://test:test@localhost:5432/test npm run migrate up`)

You should now have two tables in your DB :tada:

If you will want to change your schema later, you can e.g. add lead paragraph to posts:

Run `npm run migrate create posts lead`, edit `xxx_posts_lead.js`:

```js
exports.up = (pgm) => {
  pgm.addColumns('posts', {
    lead: { type: 'text', notNull: true },
  })
}
```

Run `npm run migrate up` and there will be new column in `posts` table :tada: :tada:

Want to know more? Read docs:

## Docs

Full docs are available at https://lorefnon.me/ts-pg-migrate/

## Explanation & Goals

_Why only Postgres?_ - By writing this migration tool specifically for postgres instead of accommodating many databases, we can actually provide a full featured tool that is much simpler to use and maintain. I was tired of using crippled database tools just in case one day we switch our database.

_Async / Sync_ - Everything is async in node, and that's great, but a migration tool should really just be a fancy wrapper that generates SQL. Most other migration tools force you to bring in control flow libraries or wrap everything in callbacks as soon as you want to do more than a single operation in a migration. Plus by building up a stack of operations, we can automatically infer down migrations (sometimes) to save even more time.

_Naming / Raw Sql_ - Many tools force you to use their constants to do things like specify data types. Again, this tool should be a fancy wrapper that generates SQL, so whenever possible, it should just pass through user values directly to the SQL. The hard part is remembering the syntax of the specific operation, not remembering how to type "timestamp"!

## Lineage

This project was started by [Theo Ephraim](https://github.com/theoephraim/), continued by [Salsita Software](https://www.salsitasoft.com/) and is now maintained by [Lorefnon](https://lorefnon.me).

## License

[MIT](./LICENSE)