How to define an optional field in protobuf 3

Question

I need to specify a message with an optional field in protobuf (proto3 syntax). In terms of proto 2 syntax, the message I want to express is something like:

Answer 1

There is a good post about this: https://itnext.io/protobuf-and-null-support-1908a15311b6

The solution depends on your actual use case:

• Handling partial update

• Support null