diesel/expression/functions/
aggregate_ordering.rs

1use sql_types::{IntoNullable, SqlOrd};
2
3sql_function! {
4    /// Represents a SQL `MAX` function. This function can only take types which are
5    /// ordered.
6    ///
7    /// # Examples
8    ///
9    /// ```rust
10    /// # #[macro_use] extern crate diesel;
11    /// # include!("../../doctest_setup.rs");
12    /// # use diesel::dsl::*;
13    /// #
14    /// # fn main() {
15    /// #     use schema::animals::dsl::*;
16    /// #     let connection = establish_connection();
17    /// assert_eq!(Ok(Some(8)), animals.select(max(legs)).first(&connection));
18    /// # }
19    #[aggregate]
20    fn max<ST: SqlOrd + IntoNullable>(expr: ST) -> ST::Nullable;
21}
22
23sql_function! {
24    /// Represents a SQL `MIN` function. This function can only take types which are
25    /// ordered.
26    ///
27    /// # Examples
28    ///
29    /// ```rust
30    /// # #[macro_use] extern crate diesel;
31    /// # include!("../../doctest_setup.rs");
32    /// # use diesel::dsl::*;
33    /// #
34    /// # fn main() {
35    /// #     use schema::animals::dsl::*;
36    /// #     let connection = establish_connection();
37    /// assert_eq!(Ok(Some(4)), animals.select(min(legs)).first(&connection));
38    /// # }
39    #[aggregate]
40    fn min<ST: SqlOrd + IntoNullable>(expr: ST) -> ST::Nullable;
41}