use async_graphql::SimpleObject;
use channel_loader::diesel::{DieselError, DieselLoader};
use db::schema::users;
use diesel::prelude::*;
use diesel_connection::PooledConnection;
use std::collections::HashMap;
derive_id! {
#[derive(Identifiable)]
#[table_name = "users"]
#[graphql(name = "UserID")]
pub struct UserId( #[column_name = "id"] i32);
}
#[derive(SimpleObject, Identifiable, Associations, Queryable, Debug, Clone)]
#[belongs_to(UserId, foreign_key = "id")]
#[table_name = "users"]
pub struct User {
pub id: i32,
pub name: String,
}
#[derive(Default)]
pub struct UserLoader;
impl DieselLoader for UserLoader {
type Key = UserId;
type Value = Vec<User>;
fn load(
conn: PooledConnection,
keys: Vec<UserId>,
) -> Result<HashMap<Self::Key, Self::Value>, DieselError> {
let users: Vec<User> = User::belonging_to(&keys)
.select(users::all_columns)
.load::<User>(&conn)?;
let grouped_users = users.grouped_by(&keys);
let mut data: HashMap<UserId, Vec<User>> = HashMap::new();
data.extend(keys.into_iter().zip(grouped_users.into_iter()));
Ok(data)
}
}
define_static_loader!(UserLoader);
attach_loader!(User, UserLoader);
