CDRS query and map

cdrs-query-and-map.rs

// include AsRust and IntoRustByName traits to provide an ability to represent
// column values as simple Rust values.
use cdrs::types::{AsRust, IntoRustByName};

struct Author {
  first_name: String,
  second_name: String
}

struct Message {
  author: Author,
  text: String,
  tags: Vec<String>
}

// ... establish session
// ... query all messages

// get frame's body
let result_frame_body = res_frame.get_body();
// then convert a body into Vec<Row>
let rows = result_frame_body.into_rows().unwrap();
let messages: Vec<Message> = rows
  .iter()
  .map(|row| {
    // get author as cdrs::types::udt::UDT
    let author_udt = row.get_by_name("author").unwrap();
    // and construct Author struct from the UDT
    let author = Author {
      first_name: author_udt.get_by_name("first_name").unwrap(),
      second_name: author_udt.get_by_name("second_name").unwrap()
    };
    // get text as String
    let text: String = row.get_by_name("text").unwrap();
    // get tags as cdrs::types::list::List and then convert it into Vec<String>
    let tags: Vec<String> = row.get_by_name("tags").as_rust().unwrap();
    return Message {
      author: author,
      text: text,
      tags: tags
    };
  })
  .collect();