diesel/expression/
assume_not_null.rsuse crate::expression::*;
use crate::query_builder::*;
use crate::query_source::joins::ToInnerJoin;
use crate::result::QueryResult;
use crate::sql_types::{DieselNumericOps, IntoNotNullable};
#[derive(Default, Debug, Copy, Clone, DieselNumericOps, ValidGrouping)]
pub struct AssumeNotNull<T>(T);
impl<T> AssumeNotNull<T> {
pub fn new(expr: T) -> Self {
AssumeNotNull(expr)
}
}
impl<T> Expression for AssumeNotNull<T>
where
T: Expression,
T::SqlType: IntoNotNullable,
<T::SqlType as IntoNotNullable>::NotNullable: TypedExpressionType,
{
type SqlType = <T::SqlType as IntoNotNullable>::NotNullable;
}
impl<T, DB> QueryFragment<DB> for AssumeNotNull<T>
where
DB: Backend,
T: QueryFragment<DB>,
{
fn walk_ast<'b>(&'b self, pass: AstPass<'_, 'b, DB>) -> QueryResult<()> {
self.0.walk_ast(pass)
}
}
impl<T, QS> AppearsOnTable<QS> for AssumeNotNull<T>
where
T: AppearsOnTable<QS>,
AssumeNotNull<T>: Expression,
{
}
impl<T: QueryId> QueryId for AssumeNotNull<T> {
type QueryId = T::QueryId;
const HAS_STATIC_QUERY_ID: bool = T::HAS_STATIC_QUERY_ID;
}
impl<T, QS> SelectableExpression<QS> for AssumeNotNull<T>
where
Self: AppearsOnTable<QS>,
QS: ToInnerJoin,
T: SelectableExpression<QS::InnerJoin>,
{
}
impl<T> SelectableExpression<NoFromClause> for AssumeNotNull<T> where
Self: AppearsOnTable<NoFromClause>
{
}