diesel_postgres_query_published_posts_with_limit.rs

1use diesel::prelude::*;
2use diesel::pg::PgConnection;
3use dotenvy::dotenv;
4use std::env;
5
6pub mod models {
7    use diesel::prelude::*;
8
9    #[derive(Queryable, Selectable)]
10    #[diesel(table_name = crate::schema::posts)]
11    #[diesel(check_for_backend(diesel::pg::Pg))]
12    pub struct Post {
13        pub id: i32,
14        pub title: String,
15        pub body: String,
16        pub published: bool,
17    }
18}
19
20pub mod schema {
21    diesel::table! {
22        posts (id) {
23            id -> Int4,
24            title -> Varchar,
25            body -> Text,
26            published -> Bool,
27        }
28    }
29}
30
31fn main() {
32    use self::models::*;
33    use self::schema::posts::dsl::*;
34
35    dotenv().ok();
36
37    let database_url = env::var("DATABASE_URL").expect("DATABASE_URL must be set");
38    let mut connection = PgConnection::establish(&database_url)
39        .unwrap_or_else(|_| panic!("Error connecting to {}", database_url));
40
41    let results = posts
42        .filter(published.eq(true))
43        .limit(5)
44        .select(Post::as_select())
45        .load(&mut connection)
46        .expect("Error loading posts");
47
48    println!("Displaying {} posts", results.len());
49    for post in results {
50        println!("{}", post.title);
51        println!("-----------\n");
52        println!("{}", post.body);
53    }
54}