diesel/query_dsl/
belonging_to_dsl.rs

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1/// Constructs a query that finds record(s) based on directional association with other record(s).
2///
3/// # Example
4///
5/// ```rust
6/// # include!("../doctest_setup.rs");
7/// # use schema::{posts, users};
8/// #
9/// # #[derive(Identifiable, Queryable)]
10/// # pub struct User {
11/// #     id: i32,
12/// #     name: String,
13/// # }
14/// #
15/// # #[derive(Debug, PartialEq)]
16/// # #[derive(Identifiable, Queryable, Associations)]
17/// # #[diesel(belongs_to(User))]
18/// # pub struct Post {
19/// #     id: i32,
20/// #     user_id: i32,
21/// #     title: String,
22/// # }
23/// #
24/// # fn main() {
25/// #     run_test();
26/// # }
27/// #
28/// # fn run_test() -> QueryResult<()> {
29/// #     let connection = &mut establish_connection();
30/// #     use self::users::dsl::*;
31/// #     use self::posts::dsl::{posts, title};
32/// let sean = users.filter(name.eq("Sean")).first::<User>(connection)?;
33/// let tess = users.filter(name.eq("Tess")).first::<User>(connection)?;
34///
35/// let seans_posts = Post::belonging_to(&sean)
36///     .select(title)
37///     .load::<String>(connection)?;
38/// assert_eq!(vec!["My first post", "About Rust"], seans_posts);
39///
40/// // A vec or slice can be passed as well
41/// let more_posts = Post::belonging_to(&vec![sean, tess])
42///     .select(title)
43///     .load::<String>(connection)?;
44/// assert_eq!(vec!["My first post", "About Rust", "My first post too"], more_posts);
45/// #     Ok(())
46/// # }
47/// ```
48pub trait BelongingToDsl<T> {
49    /// The query returned by `belonging_to`
50    type Output;
51
52    /// Get the record(s) belonging to record(s) `other`
53    fn belonging_to(other: T) -> Self::Output;
54}
diesel/query_dsl/belonging_to_dsl.rs

diesel/query_dsl/
belonging_to_dsl.rs
