Performing mutations

Mutation queries make changes somewhere - ie., perform a task, or update a record.

Mutating operations are defined in Taxi using the write modifier:

service FlightsService {
  write operation bookFlight(BookingRequest):BookingConfirmation
  write operation sendFlightManifest(Manifest):ManifestConfirmation
}

Mutating operations are excluded from being invoked during a query (ie., anything with a find {} or stream {} directive.)

Instead, they are invoked using a call directive.

find { Passengers[] }
call FlightsService::sendFlightManifest

In this example, a list of Passengers is fetched, and converted into a Manifest to call the sendFlightManifest operation of the FlightsService.

Many different data sources support mutations, such as databases, Kafka, MongoDB, and Hazelcast.

Consult the docs for the relevant data source to learn more.