#[derive(Clone, Debug)]
pub struct SelectTwo<E, F>
where
    E: EntityTrait,
    F: EntityTrait,
{
    pub(crate) query: SelectStatement,
    pub(crate) entity: PhantomData<(E, F)>,
}

impl<E, F> SelectTwo<E, F>
where
    E: EntityTrait,
    F: EntityTrait,
{
    pub(crate) fn new(query: SelectStatement) -> Self {
        let myself = Self {
            query,
            entity: PhantomData,
        };
        myself.prepare_select()
    }

    fn prepare_select(mut self) -> Self {
        for col in <F::Column as Iterable>::iter() {
            let alias = format!("{}{}", SELECT_B, col.to_string().as_str());
            self.query.expr(SelectExpr {
                expr: col.into_simple_expr(),
                alias: Some(SeaRc::new(Alias::new(&alias))),
            });
        }
        self
    }

    fn apply_alias(mut self, pre: &str) -> Self { ... }

    pub fn select_also<G>(mut self, _: G) -> SelectThree<E, F, G>
    where
        G: EntityTrait,
    {
        self = self.apply_alias(SELECT_C);
        SelectThree::new(self.into_query())
    }
}

macro_rules! impl_trait {
    ( $trait: ident ) => {
        impl<E, F> $trait for SelectTwo<E, F>
        where
            E: EntityTrait,
            F: EntityTrait,
        {
            type QueryStatement = SelectStatement;

            fn query(&mut self) -> &mut SelectStatement {
                &mut self.query
            }
        }
    };
}

impl_trait!(QuerySelect);
impl_trait!(QueryFilter);
impl_trait!(QueryOrder);