Diesel, a Rust ORM Better solution

[incker]

Hello,
I do not know where to write you, so will write you here.
I know better solution for this article

https://leward.eu/2018/09/23/diesel-rust-notes.html

#[derive(Queryable, PartialEq)]
pub struct News {
    pub id: i64,
    pub content: String,
    pub date: Option<NaiveDateTime>,
    pub title: String,
    pub cover: Cover, // Here I want to have a Cover, not a cover_id
}


#[derive(Queryable, PartialEq)]
pub struct Cover {
    pub id: i64,
    pub name: String,
    pub url: String,
}


fn get_latest_news() -> Vec<News> {
    use schema::cover;
    use schema::news;
    let connection = &*get_pooled_connection();

    news::table
        .inner_join(cover::table)
        .limit(5)
        .select((
            news::dsl::id,
            news::dsl::content,
            news::dsl::date,
            news::dsl::title,
            (cover::dsl::id, cover::dsl::name, cover::dsl::url)
        ))
        .order(news::date.desc())
        .load::<News>(connection) // To this point we get the result as a tuple.
        .expect("Error loading news") // Another panic waiting to happen!
}

Forward thank you if you will also fix article

[Leward]

Hi! Thank for reading my article and commenting here!

Let me have a look and re-run the snippets when I have a bit of time.

[incker]

Also I want to admit to that article that no need to make always copy or clone as rust can destruct nearly everything like

let (num1 num2) = (1, 2);

or

let MyStruct { data: my_struct_data } = my_struct;
println!("{}", my_struct_data );

Even function input argument can be a destructor.
It allows not copy data but give data in owning

[Leward]

I had a quick look a sample code a gave it a go. What you are suggesting does work, which is a good thing.

As to, which solution is better (besides my use of clone() out of laziness), it depends on what you prefer (my humble opinion):

• The solution I gave allows not to have to select which column to select, hower it needs an extra step to step to to build News
• Your solution requires to pass all the required fields in the query. Given this is validated by the compiler it's kind of nice.

I've added your suggestion at the end of the article. Thank you for having a look into this 🙏

[incker]

Thank you too, for paying attention!)