Need an example for connecting to MongoDB on Rust

[ayyagari-dalalstreet]

I have tried the methods given by the doc url[https://rocket.rs/v0.4/guide/state/#databases] and explored the drivers but getting an issue of pbkdf2 version is unmatched.

# Full Error message here

failed to select a version for the requirement `pbkdf2 = "^0.2.0"`
candidate versions found which didn't match: 0.9.0, 0.8.0, 0.7.5, ...
location searched: crates.io index
required by package `mongodb v0.3.12`
    ... which satisfies dependency `mongodb = "^0.3.12"` of package `rocket_contrib v0.4.10`
    ... which satisfies dependency `rocket_contrib = "^0.4.10"` of package `rocket_mongodo v0.1.0 

Unable to solve with the help of the current resources and findings. Need help with an small example on connecting Rocket with MongoDB

As a author I am new to Rust and my previous background was working with JS and Python

[somehowchris]

@ayyagari-dalalstreet Do you need mongodb with rocket_contrib or would wither as an odm be fine? Just asking cause I could help out wither as I was using it with rocket.

In case of wither:

use rocket::State;
use rocket::serde::json::Json;
use rocket::serde::{Deserialize, Serialize};
use wither::bson::{doc, oid::ObjectId};
use wither::prelude::*;
use futures::stream::StreamExt;

#[cfg(debug_assertions)]
use dotenv::dotenv;

mod data {
    mod entity {
        #[derive(Debug, Model, Serialize, Deserialize)]
        #[model(index(keys = r#"doc!{"name": 1}"#, options = r#"doc!{"unique": true}"#))]
        struct Data {
            #[serde(rename = "_id", skip_serializing_if = "Option::is_none")]
            pub id: Option<ObjectId>,
            pub name: String,
        }

        impl Data {
            pub async fn sync_db(db: &wither::mongodb::Database) -> () {
                Data::sync(db).await.unwrap();
            }
        }
    }
}

pub struct MongoState {
    db: wither::mongodb::Database,
}

#[get("/")]
async fn get_all_data(db: &State<MongoState>) -> Json<Vec<data::entity::Data>> {
    let mut cursor = data::entity::Data::find(&db_state.db, None, None).await.unwrap();

    let mut results = Vec::new();

    while let Some(data_point) = cursor.next().await {
        results.push(data_point);
    }

    return Json(results);
}


#[launch]
async fn rocket() -> _ {
    #[cfg(debug_assertions)]
    info!("Loading .env file if present");

    #[cfg(debug_assertions)]
    dotenv().ok();

    let db = Client::with_uri_str(
        std::env::var("MONGO_DB_URL")
            .expect("Could not detect env variable MONGO_DB_URL to connect to the db")
            .as_str(),
    )
    .await
    .unwrap()
    .database(
        std::env::var("MONGO_DB_NAME")
            .expect("Could not detect MONGO_DB_NAME to name the use database")
            .as_str(),
    );

    // Do your index syncing if needed 
    data::entity::Data::sync_db(&db).await;

    rocket::build().mount("/data", routes![ get_data ]).manage(MongoState{ db })
}

[Guileas]

@ayyagari-dalalstreet I've updated your issue (#1962).
This repo (rust-rocket-sample) contain everything you need to have a working connection to mongodb using rocket

Dependencies version:
rocket = "0.5.0-rc.1"
mongodb = "2.1.0"