Trait diesel::query_dsl::methods::DistinctOnDsl

source ·
pub trait DistinctOnDsl<Selection> {
    type Output;

    // Required method
    fn distinct_on(self, selection: Selection) -> DistinctOn<Self, Selection>;
Available on crate feature postgres_backend only.
Expand description

The distinct_on method

This trait should not be relied on directly by most apps. Its behavior is provided by QueryDsl. However, you may need a where clause on this trait to call distinct_on from generic code.

Required Associated Types§


type Output

The type returned by .distinct_on

Required Methods§


fn distinct_on(self, selection: Selection) -> DistinctOn<Self, Selection>

See the trait documentation



impl<S, Selection> DistinctOnDsl<Selection> for Alias<S>
where S: AliasSource, Selection: SelectableExpression<Self>, Self: QuerySource + AsQuery<Query = SelectStatement<FromClause<Self>>>, SelectStatement<FromClause<Self>>: DistinctOnDsl<Selection>, <Self as QuerySource>::DefaultSelection: Expression<SqlType = <Self as AsQuery>::SqlType> + ValidGrouping<()>, <Self as AsQuery>::SqlType: TypedExpressionType,


impl<T, Selection> DistinctOnDsl<Selection> for T