Function diesel::dsl::avg

pub fn avg<ST, T>(t: T) -> Avg<T> where
    ST: Foldable,
    T: Expression<SqlType = ST>, 

Represents a SQL AVG function. This function can only take types which are Foldable.

Examples

diesel::insert_into(numbers)
    .values(&vec![number.eq(1), number.eq(2)])
    .execute(&conn)?;
let average = numbers.select(avg(number)).get_result(&conn)?;
let expected = "1.5".parse::<BigDecimal>().unwrap();
assert_eq!(Some(expected), average);