Trait cqrs_es::Query

pub trait Query<A, E>: Debug + Default + Serialize + DeserializeOwned where
    E: DomainEvent<A>,
    A: Aggregate, {
    fn update(&mut self, event: &EventEnvelope<A, E>);
}

A Query is a read element in a CQRS system. As events are emitted multiple downstream queries are updated to reflect the current state of the system. A query may also be referred to as a 'view', the concepts are identical but 'query' is used here to conform with CQRS nomenclature.

Queries are generally serialized for persistence, usually in a standard database, but a query could also utilize messaging platform or other asynchronous, eventually-consistent systems.

Required methods

fn update(&mut self, event: &EventEnvelope<A, E>)

Each implemented query is responsible for updating its stated based on events passed via this method.

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Implementors

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