Derive Macro FromSqlRow 

#[derive(FromSqlRow)]
{
    // Attributes available to this derive:
    #[diesel]
}

Implements Queryable for types that correspond to a single SQL type. The type must implement FromSql.

This derive is mostly useful to implement support deserializing into rust types not supported by Diesel itself.

There are no options or special considerations needed for this derive.

Expanded Code

Expanded Code

Input

#[derive(FromSqlRow)]
enum Foo {
    Bar,
    Baz,
}

Expanded Code

Expanded code might use diesel internal API's and is only shown for educational purpose

The macro expands the input to the following Rust code:

const _: () = {
    use diesel;
    impl<__DB, __ST> diesel::deserialize::Queryable<__ST, __DB> for Foo
    where
        __DB: diesel::backend::Backend,
        __ST: diesel::sql_types::SingleValue,
        Self: diesel::deserialize::FromSql<__ST, __DB>,
    {
        type Row = Self;
        fn build(row: Self) -> diesel::deserialize::Result<Self> {
            Ok(row)
        }
    }
};