> For the complete documentation index, see [llms.txt](https://docs.angel-dart.dev/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.angel-dart.dev/orm/migrations.md).

# Migrations

Angel's ORM ships with support for running database migrations, using a system modeled over [that of Laravel](https://laravel.com/docs/5.7/migrations).

An example is shown below:

```dart
class UserMigration implements Migration {
  @override
  void up(Schema schema) {
    schema.create('users', (table) {
      table
        ..serial('id').primaryKey()
        ..varChar('username', length: 32).unique()
        ..varChar('password')
        ..boolean('account_confirmed').defaultsTo(false);
    });
  }

  @override
  void down(Schema schema) {
    schema.drop('users');
  }
}
```

Migrations can be used to either create, alter, or drop database tables.

For more in-depth documentation, consult the `angel_migration` documentation:

<https://github.com/angel-dart/migration>

If you use `angel_orm_generator`, then a migration will be generated by default for each class annotated with `@orm`.

To disable this:

```dart
@Orm(generateMigrations: false)
abstract class _MyModel extends Model {}
```

## Running Migrations

Using `package:angel_migration_runner`, we can create executables that run our database migrations:

```dart
import 'package:angel_migration_runner/angel_migration_runner.dart';
import 'package:angel_migration_runner/postgres.dart';
import 'package:postgres/postgres.dart';
import '../../angel_migration/example/todo.dart';

var migrationRunner = PostgresMigrationRunner(
  PostgreSQLConnection('127.0.0.1', 5432, 'test'),
  migrations: [
    UserMigration(),
    TodoMigration(),
  ],
);
```

Running this file will produce output like the following:

```
Executes Angel migrations.

Usage: migration_runner <command> [arguments]

Global options:
-h, --help    Print this usage information.

Available commands:
  help       Display help information for migration_runner.
  refresh    Resets the database, and then re-runs all migrations.
  reset      Resets the database.
  rollback   Undoes the last batch of migrations.
  up         Runs outstanding migrations.

Run "migration_runner help <command>" for more information about a command.
```

The migration runner keeps track of a `migrations` table, in order to be able to keep track of which migrations it has run.


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://docs.angel-dart.dev/orm/migrations.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.