Before starting with the ORM, it is highly recommended to familiar one’s self withpackage:angel_serialize, as it is the foundation for package:angel_orm:

https://github.com/angel-dart/serialize

To enable the ORM for a given model, simply add the @orm annotation to its definition:

@orm
@serializable
abstract class _Todo {
    bool get isComplete;
    String get text;
    @Column(type: ColumnType.long)
    int get score;
}

The generator will produce a TodoQuery class, which contains fields corresponding to each field declared in _Todo.Each of TodoQuery‘s fields is a subclass of SqlExpressionBuilder, corresponding to the given type. For example, TodoQuerywould look something like:

class TodoQuery extends Query<Todo, TodoQueryWhere> {
    BooleanSqlExpressionBuilder get isComplete;
    StringSqlExpressionBuilder get text;
    NumericSqlExpressionBuilder<int> get score;
}

Thus, you can query the database using plain-old-Dart-objects (PODO’s):

Future<List<Todo>> leftToDo(QueryExecutor executor) async {
    var query = TodoQuery()..where.isComplete.isFalse;
    return await query.get(executor);
}
Future<void> markAsComplete(Todo todo, QueryExecutor executor) async {
    var query = TodoQuery()
        ..where.id.equals(todo.idAsInt)
        ..values.isComplete = true;
    await query.updateOne(executor);
}

The glue holding everything together is the QueryExecutor interface. To support the ORMfor any arbitrary database, simply extend the class and implement its abstract methods.

Consumers of a QueryExecutor typically inject it into the app’sdependency injection container:

app.container.registerSingleton<QueryExecutor>(PostgresExecutor(...));

At the time of this writing, there is only support for PostgreSQL, though more databases maybe added eventually.