Trait diesel::prelude::FirstDsl

pub trait FirstDsl<Conn>: LimitDsl + LoadDsl<Conn> {
    fn first<U>(self, conn: &Conn) -> QueryResult<U>
    where
        Limit<Self>: LoadQuery<Conn, U>,
    { ... }
}

Provided Methods

fn first<U>(self, conn: &Conn) -> QueryResult<U> where
    Limit<Self>: LoadQuery<Conn, U>, 

Attempts to load a single record. Returns Ok(record) if found, and Err(NotFound) if no results are returned. If the query truly is optional, you can call .optional() on the result of this to get a Result<Option<U>>.

Implementors

• impl<Conn, T: LimitDsl + LoadDsl<Conn>> FirstDsl<Conn> for T