diesel/expression/
assume_not_null.rs

1use crate::expression::*;
2use crate::query_builder::*;
3use crate::query_source::joins::ToInnerJoin;
4use crate::result::QueryResult;
5use crate::sql_types::{DieselNumericOps, IntoNotNullable};
6
7#[derive(Default, Debug, Copy, Clone, DieselNumericOps, ValidGrouping)]
8pub struct AssumeNotNull<T>(T);
9
10impl<T> AssumeNotNull<T> {
11    pub fn new(expr: T) -> Self {
12        AssumeNotNull(expr)
13    }
14}
15
16impl<T> Expression for AssumeNotNull<T>
17where
18    T: Expression,
19    T::SqlType: IntoNotNullable,
20    <T::SqlType as IntoNotNullable>::NotNullable: TypedExpressionType,
21{
22    type SqlType = <T::SqlType as IntoNotNullable>::NotNullable;
23}
24
25impl<T, DB> QueryFragment<DB> for AssumeNotNull<T>
26where
27    DB: Backend,
28    T: QueryFragment<DB>,
29{
30    fn walk_ast<'b>(&'b self, pass: AstPass<'_, 'b, DB>) -> QueryResult<()> {
31        self.0.walk_ast(pass)
32    }
33}
34
35impl<T, QS> AppearsOnTable<QS> for AssumeNotNull<T>
36where
37    T: AppearsOnTable<QS>,
38    AssumeNotNull<T>: Expression,
39{
40}
41
42impl<T: QueryId> QueryId for AssumeNotNull<T> {
43    type QueryId = T::QueryId;
44
45    const HAS_STATIC_QUERY_ID: bool = T::HAS_STATIC_QUERY_ID;
46}
47
48impl<T, QS> SelectableExpression<QS> for AssumeNotNull<T>
49where
50    Self: AppearsOnTable<QS>,
51    QS: ToInnerJoin,
52    T: SelectableExpression<QS::InnerJoin>,
53{
54}
55
56impl<T> SelectableExpression<NoFromClause> for AssumeNotNull<T> where
57    Self: AppearsOnTable<NoFromClause>
58{
59}