npm package: @ovotech/pg-sql-migrate
Description: migrate db using postgres sql files
Author: Ivan Kerin
Latest version: 4.1.0

# Postgres migration tool with plain sql

A very small library for running sql migrations with postgres. It differs from the numerous other libs in this domain by being very minimal, using only raw timestamped sql files. No "down" migrations are provided by design, as that is usually a bad idea in production anyway.

## Using with CLI

```bash
yarn add @ovotech/pg-sql-migrate
```

add a configuration file, which by default is `./pg-sql-migrate.config.json` to configure the connection:

```json
{
  "client": "postgresql://postgres:dev-pass@localhost:5432/postgres",
  "directory": "migrations",
  "table": "migrations"
}
```

The default values for "directory" and "table" configuration is `migrations` but you can override that if you need to.

Instead of a string you can use an object. This is passed directly to pg https://node-postgres.com/features/connecting

```json
{
  "client": {
    "user": "postgres",
    "password": "dev-pass",
    "host": "localhost",
    "database": "postgres",
    "port": 5432
  }
}
```

To create new migrations in the designated directory you can run:

```bash
yarn migrate create my_migration
```

This will create a file `migrations/<timestamp>_my_migration.pgsql` that you can place raw sql into. After that, you can run the migration(s) by calling

```bash
yarn migrate execute
```

You can also specify the configuration as cli options

```bash
yarn migrate execute --config-directory ~/my/dir/migrations --config-table my-table --config-client postgresql://localhost:5432/my-database
```

In you code you can run it as a library

```typescript
import { migrate } from '@ovotech/pg-sql-migrate';

await migrate();
```

## Environment variables

In your config file you can use environment variables.

For example, if you have the env var `PG_USER_PASS` setup, you can access it with:

```json
{
  "client": "postgresql://postgres:${PG_USER_PASS}@localhost:5432/postgres",
  "directory": "migrations"
  "table" "migrations"
}
```

## Using the library

You can choose a different location for the config file, or to just input its contents directly:

```typescript
import { migrate } from '@ovotech/pg-sql-migrate';
import { createLogger } from 'winston';

await migrate();

await migrate({ config: 'custom-config.json' });

await migrate({
  config: {
    client: 'postgresql://postgres:dev-pass@localhost:5432/postgres',
    // Custom table location
    table: 'my_table',
    // Custom directory for migration files
    directory: 'migrations_dir',
  },
});

// Custom logger
const logger = createLogger();
await migrate({ logger });

// Dry run
await migrate({ dryRun: true });
```

## Distabling transactions for some migrations

By default migrations are wrapped in transactions, but there are some PG operations that cannot be performed inside a transaction. You can disable this for a specific transaction by adding a prefix

```sql
-- pg-sql-migrate: DISABLE TRANSACTION
ALTER TYPE my_type ADD VALUE 'VAL2' AFTER 'VAL1';
```

## Running the tests

You can run the tests with:

```bash
yarn test
```

### Coding style (linting, etc) tests

Style is maintained with prettier and eslint

```
yarn lint
```

## Deployment

Deployment is preferment by circleci automatically on merge / push to master, but you'll need to bump the package version numbers yourself.

## Contributing

Have a bug? File an issue with a simple example that reproduces this so we can take a look & confirm.

Want to make a change? Submit a PR, explain why it's useful, and make sure you've updated the docs (this file) and the tests (see [test folder](test)).

## License

This project is licensed under Apache 2 - see the [LICENSE](LICENSE) file for details