Diesel: Queryable Numeric is not implemented for BigDecimal

[fundon]

Setup

Versions

• Rust: 1.26.1
• Diesel: 1.3.1
• Database: PostgreSQL 10
• Operating System macOS 10.13.5

Feature Flags

• diesel:

diesel = { git = "https://github.com/diesel-rs/diesel", tag ="v1.3.1", default-features = false, features = ["chrono", "serde_json", "uuid", "network-address", "numeric", "r2d2", "postgres"] }

Problem Description

let results = contracts.limit(5).load::<Contract>(&connection).expect(
   |                                      ^^^^ the trait `diesel::Queryable<diesel::sql_types::Numeric, diesel::pg::Pg>` is not implemented for `bigdecimal::BigDecimal`

Codes:
main.rs

#[macro_use]
extern crate diesel;
extern crate bigdecimal;
extern crate chrono;
extern crate dotenv;
extern crate serde;
#[macro_use]
extern crate serde_json;
#[macro_use]
extern crate serde_derive;

use diesel::pg::PgConnection;
use diesel::prelude::*;
use dotenv::dotenv;
use std::env;

mod schema;

use bigdecimal::BigDecimal;
use chrono::{DateTime, Utc};
use diesel::prelude::*;
use diesel::*;
use serde_json::Value;

#[derive(Queryable)]
pub struct Contract {
    pub id: i32,
    pub conditions: Value,
    pub state: i16,
    pub self_stake: BigDecimal,
    pub rival_stake: BigDecimal,
    pub created_at: DateTime<Utc>,
    pub updated_at: DateTime<Utc>,
}

pub fn establish_connection() -> PgConnection {
    dotenv().ok();

    let database_url = env::var("DATABASE_URL").expect("DATABASE_URL must be set");
    PgConnection::establish(&database_url).expect(&format!("Error connecting to {}", database_url))
}

fn main() {
    let connection = establish_connection();

    use self::diesel::prelude::*;
    use self::schema::contracts::dsl::*;

    let results = contracts
        .limit(5)
        .load::<Contract>(&connection)
        .expect("Error loading posts");

    println!("Displaying {} posts", results.len());
    for post in results {
        println!("{}", post.id);
        println!("----------\n");
        println!("{}", post.conditions);
        println!("{}", post.self_stake);
        println!("{}", post.rival_stake);
    }
}

schema.rs

table! {
    contracts (id) {
        id -> Int4,
        conditions -> Json,
        state -> Int2,
        self_stake -> Numeric,
        rival_stake -> Numeric,
        created_at -> Timestamptz,
        updated_at -> Timestamptz,
    }
}

NOTE: I'm noob.

[weiznich]

That sounds like you are using different versions of bigdecimal. Please doublecheck that your crate depends on the same version as diesel. (Cargo tree could be handy for this)

[weiznich]

Closed because this does not contain something actionable for the diesel team.
(If this does not solve the issue, just continue asking here or even better in our gitter room)

[fundon]

thank you. fixed

[derekdreery]

It would be good if diesel re-exported BigDecimal when the numeric feature is enabled, then there's no chance of a clash.

[cjen07]

thanks a lot