Rust: PostgreSQL のデータを読む (Read)


Cargo.toml
[package]
name = "postgres_read"
version = "0.1.0"
edition = "2018"

[dependencies]
postgres = "*"
src/main.rs
// --------------------------------------------------------------------
/*
    postgres_read/src/main.rs

                    Jul/24/2020
*/
// --------------------------------------------------------------------
use postgres::{Client, NoTls, Error};

// --------------------------------------------------------------------
fn main() -> Result<(), Error> {
    eprintln!("*** start ***");
    let mut client = Client::connect("postgresql://scott:tiger123@localhost/city", NoTls)?;

    for row in client.query("SELECT id,name,population,date_mod FROM cities", &[])? {
        let id:String = row.get(0);
        let name:String = row.get(1);
        let population:i32 = row.get(2);
        let date_mod:String = row.get(3);
        println!("{}\t{}\t{}\t{}",id,name,population,date_mod);
    };  

    eprintln!("*** end ***");
    Ok(())

}

// --------------------------------------------------------------------

実行コマンド

cargo run