Queries

Queries are about requesting and retrieving data without affecting the system's state. They don't interact with the domain. Queries are read-only operations and are used to fetch data for the application's read model. The update of the read model is handled by the commands.

• Data-Focused: Queries are solely concerned with data retrieval.
• Side-Effect-Free: They do not alter the state of the system.
• Read-Oriented: Queries interact with the read model of the application.

Creating Queries

#[derive(Deserialize)]
pub struct GetTodoListQuery {}

Implementing Queries

Queries are usually implemented to interact with the read model, fetching data as per the application's requirements.

#[async_trait]
impl<R> Execute<R> for GetTodoListQuery
where
    R: TodoListRepository + Send + Sync,
{
    type Output = TodoListProjection;
 
    async fn execute(&self, runtime: &R) -> AnyResult<TodoListProjection> {
        runtime.fetch().await
    }
}