Improve flight sql examples

[lewiszlw]

Which issue does this PR close?

Implement get_flight_info_tables and remove unimplemented methods.

Rationale for this change

What changes are included in this PR?

Are these changes tested?

Are there any user-facing changes?

[alamb]

Thank you @lewiszlw -- this looks really nice to me

[alamb]

removing this code means it falls back to the default implementation (which also returns Not implemented)

Seems like a nice change to me 👍

[alamb]

👍

[alamb]

Nice! I think you can make this code simpler using FlightInfo::new() as shown on the examples in https://docs.rs/arrow-flight/latest/arrow_flight/struct.FlightInfo.html

// Create a new FlightInfo
let flight_info = FlightInfo::new()
  // Encode the Arrow schema
  .try_with_schema(&schema))
  .expect("encoding failed")
  .with_endpoint(
     FlightEndpoint::new()
       .with_ticket(ticket)
     )
   )
  .with_descriptor(FlightDescriptor::new_cmd(Default::default()));

[lewiszlw]

Thanks for the suggestion!
.with_descriptor(FlightDescriptor::new_cmd(Default::default())) can not be compiled due to

cannot infer type for type parameter `impl Into<Bytes>` declared on the associated function `new_cmd`

So I changed to

        let info = FlightInfo::new()
            // Encode the Arrow schema
            .try_with_schema(&schema)
            .expect("encoding failed")
            .with_endpoint(FlightEndpoint::new().with_ticket(ticket))
            .with_descriptor(FlightDescriptor {
                r#type: DescriptorType::Cmd.into(),
                cmd: Default::default(),
                path: vec![],
            });

[alamb]

Thanks agian @lewiszlw

[alamb]

😍