use std::marker::PhantomData;
use super::*;
use crate::backend::Backend;
use crate::query_builder::*;
use crate::result::QueryResult;
use crate::serialize::ToSql;
use crate::sql_types::{DieselNumericOps, HasSqlType, SqlType};
#[doc(hidden)] #[derive(Debug, Clone, Copy, DieselNumericOps)]
pub struct Bound<T, U> {
item: U,
_marker: PhantomData<T>,
}
impl<T, U> Bound<T, U> {
#[doc(hidden)] pub fn new(item: U) -> Self {
Bound {
item,
_marker: PhantomData,
}
}
}
impl<T, U> Expression for Bound<T, U>
where
T: SqlType + TypedExpressionType,
{
type SqlType = T;
}
impl<T, U, DB> QueryFragment<DB> for Bound<T, U>
where
DB: Backend + HasSqlType<T>,
U: ToSql<T, DB>,
{
fn walk_ast<'b>(&'b self, mut pass: AstPass<'_, 'b, DB>) -> QueryResult<()> {
pass.push_bind_param(&self.item)?;
Ok(())
}
}
impl<T: QueryId, U> QueryId for Bound<T, U> {
type QueryId = Bound<T::QueryId, ()>;
const HAS_STATIC_QUERY_ID: bool = T::HAS_STATIC_QUERY_ID;
}
impl<T, U, QS> SelectableExpression<QS> for Bound<T, U> where Bound<T, U>: AppearsOnTable<QS> {}
impl<T, U, QS> AppearsOnTable<QS> for Bound<T, U> where Bound<T, U>: Expression {}
impl<T, U, GB> ValidGrouping<GB> for Bound<T, U> {
type IsAggregate = is_aggregate::Never;
}