Rust sqlx example

sqlx_postgres.rs

use futures::TryStreamExt;
use sqlx::postgres::{PgPoolOptions, PgRow};
use sqlx::{Error, PgPool, Row};
use uuid::Uuid;

#[derive(sqlx::FromRow, Debug)]
struct People {
    id: i32,
    name: String,
}

#[derive(Debug, sqlx::FromRow)]
struct GeneratedId {
    id: i32,
}

async fn insert_person(pool: &PgPool, name: String) -> Result<GeneratedId, Error> {
    let sql = "INSERT INTO dino.People (name) VALUES ($1) returning id";
    let id = sqlx::query_as::<_, GeneratedId>(sql)
        .bind(name)
        .fetch_one(pool)
        .await?;

    Ok(id)
}

#[tokio::main]
async fn main() -> Result<(), sqlx::Error> {
    let pool = PgPoolOptions::new()
        .max_connections(3)
        .connect("postgres://postgres:pw@localhost/postgres")
        .await?;

    let uuid = Uuid::new_v4();

    let id = insert_person(&pool, format!("person {}", uuid)).await?;

    println!("inserted id: {}", id.id);

    // I could have used fetch_all to get a Vec and not a stream
    let mut stream = sqlx::query_as::<_, People>("SELECT * FROM dino.People").fetch(&pool);

    // iterate on stream
    while let Some(people) = stream.try_next().await? {
        println!("{} {}", people.id, people.name);
    }

    let count_row: PgRow = sqlx::query("SELECT COUNT(*) FROM dino.People")
        .fetch_one(&pool)
        .await?;

    let count: i64 = count_row.get(0);

    println!("Count: {}", count);

    Ok(())
}

Cargo.toml

[package]
name = "sqlx_stuff"
version = "0.1.0"
edition = "2021"

[dependencies]
tokio = { version = "1.36.0", features = ["rt", "rt-multi-thread", "macros", "time","sync"] }
sqlx = { version = "0.7.3", features = [ "runtime-tokio","postgres" ] }
futures = "0.3.30"
uuid= { version = "1.7.0", features = ["v4", "fast-rng"] }

Output

inserted id: 4
1 Dino
2 Jenny
3 person 22fdc09e-7a89-42b8-bcf2-6e82ffded0d8
4 person 88203d90-6a7b-428e-88e6-6b7a8efbc77b
Count: 4