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.