Trait ValidGrouping 

pub trait ValidGrouping<GroupByClause> {
    type IsAggregate;
}

Is this expression valid for a given group by clause?

Implementations of this trait must ensure that aggregate expressions are not mixed with non-aggregate expressions.

For generic types, you can determine if your sub-expressions can appear together using the MixedAggregates trait.

GroupByClause will be a tuple containing the set of expressions appearing in the GROUP BY portion of the query. If there is no GROUP BY, it will be ().

This trait can be derived

Required Associated Types

type IsAggregate

Is this expression aggregate?

This type should always be one of the structs in the is_aggregate module. See the documentation of those structs for more details.

Implementations on Foreign Types

impl<GB> ValidGrouping<GB> for ()

type IsAggregate = Never

impl<T, __GroupByClause> ValidGrouping<__GroupByClause> for (T₁, T₂, …, Tₙ)

where T: ValidGrouping<__GroupByClause>,

type IsAggregate = <T as ValidGrouping<__GroupByClause>>::IsAggregate

impl<T: ValidGrouping<GB> + ?Sized, GB> ValidGrouping<GB> for &T

type IsAggregate = <T as ValidGrouping<GB>>::IsAggregate

impl<T: ValidGrouping<GB> + ?Sized, GB> ValidGrouping<GB> for Box<T>

type IsAggregate = <T as ValidGrouping<GB>>::IsAggregate

Implementors

impl<L, R, __GroupByClause> ValidGrouping<__GroupByClause> for Concat<L, R>

where L: ValidGrouping<__GroupByClause>, R: ValidGrouping<__GroupByClause>, <L as ValidGrouping<__GroupByClause>>::IsAggregate: MixedAggregates<<R as ValidGrouping<__GroupByClause>>::IsAggregate>,

type IsAggregate = <<L as ValidGrouping<__GroupByClause>>::IsAggregate as MixedAggregates<<R as ValidGrouping<__GroupByClause>>::IsAggregate>>::Output

impl<QS, ST, DB, GB, IsAggregate> ValidGrouping<GB> for dyn BoxableExpression<QS, DB, GB, IsAggregate, SqlType = ST> + '_

type IsAggregate = IsAggregate

impl<Query, Value, GB> ValidGrouping<GB> for UncheckedBind<Query, Value>

type IsAggregate = Never

impl<S, C1, C2> ValidGrouping<AliasedField<S, C1>> for AliasedField<S, C2>

where S: AliasSource, C1: Column<Table = S::Target>, C2: Column<Table = S::Target> + ValidGrouping<C1, IsAggregate = Yes>,

type IsAggregate = Yes

impl<S, C> ValidGrouping<()> for AliasedField<S, C>

where S: AliasSource, C: Column<Table = S::Target>,

type IsAggregate = No

impl<ST, I, GB> ValidGrouping<GB> for Many<ST, I>

where ST: SingleValue, I: AsExpression<ST>, I::Expression: ValidGrouping<GB>,

Available on crate feature i-implement-a-third-party-backend-and-opt-into-breaking-changes only.

type IsAggregate = <<I as AsExpression<ST>>::Expression as ValidGrouping<GB>>::IsAggregate

impl<ST, T, GB> ValidGrouping<GB> for SqlLiteral<ST, T>

type IsAggregate = Never

impl<T, GB> ValidGrouping<GB> for Exists<T>

where Subselect<T, Bool>: ValidGrouping<GB>,

Available on crate feature i-implement-a-third-party-backend-and-opt-into-breaking-changes only.

type IsAggregate = <Subselect<T, Bool> as ValidGrouping<GB>>::IsAggregate

impl<T, U, __GroupByClause> ValidGrouping<__GroupByClause> for In<T, U>

where T: ValidGrouping<__GroupByClause>, U: ValidGrouping<__GroupByClause>, <T as ValidGrouping<__GroupByClause>>::IsAggregate: MixedAggregates<<U as ValidGrouping<__GroupByClause>>::IsAggregate>,

Available on crate feature i-implement-a-third-party-backend-and-opt-into-breaking-changes only.

type IsAggregate = <<T as ValidGrouping<__GroupByClause>>::IsAggregate as MixedAggregates<<U as ValidGrouping<__GroupByClause>>::IsAggregate>>::Output

impl<T, U, __GroupByClause> ValidGrouping<__GroupByClause> for NotIn<T, U>

where T: ValidGrouping<__GroupByClause>, U: ValidGrouping<__GroupByClause>, <T as ValidGrouping<__GroupByClause>>::IsAggregate: MixedAggregates<<U as ValidGrouping<__GroupByClause>>::IsAggregate>,

Available on crate feature i-implement-a-third-party-backend-and-opt-into-breaking-changes only.

type IsAggregate = <<T as ValidGrouping<__GroupByClause>>::IsAggregate as MixedAggregates<<U as ValidGrouping<__GroupByClause>>::IsAggregate>>::Output

impl<Whens, E, __GroupByClause> ValidGrouping<__GroupByClause> for CaseWhen<Whens, E>

where Whens: ValidGrouping<__GroupByClause>, E: ValidGrouping<__GroupByClause>, <Whens as ValidGrouping<__GroupByClause>>::IsAggregate: MixedAggregates<<E as ValidGrouping<__GroupByClause>>::IsAggregate>,

type IsAggregate = <<Whens as ValidGrouping<__GroupByClause>>::IsAggregate as MixedAggregates<<E as ValidGrouping<__GroupByClause>>::IsAggregate>>::Output

impl<__GroupByClause> ValidGrouping<__GroupByClause> for now

type IsAggregate = Never

impl<__GroupByClause> ValidGrouping<__GroupByClause> for today

type IsAggregate = Never