Basic Functionality

Angel

Search…

Primary version

Introduction

Migration from Angel 1.1.x

Basic Functionality

Before starting with the ORM, it is highly recommended to familiar one's self with package: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, TodoQuery would 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 ORM for any arbitrary database, simply extend the class and implement its abstract methods.
Consumers of a QueryExecutor typically inject it into the app's dependency injection container:
app.container.registerSingleton<QueryExecutor>(PostgresExecutor(...));
At the time of this writing, there is only support for PostgreSQL, though more databases may be added eventually.

About

Relations

Last modified 3yr ago

Copy link