Basic Functionality
Before starting with the ORM, it is highly recommended to familiar one's self with package:angel3_serialize, as it is the foundation for package:angel3_orm:
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.
Last modified 2mo ago
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