Trait GroupByIdentity 

pub trait GroupByIdentity {
    type Identity;
}

Extracts the “base column” identity from an expression for GROUP BY matching.

AliasedExpr<Col> → Col, bare column → Self.

Required Associated Types

type Identity

Dyn Compatibility

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors

impl<E, Name> GroupByIdentity for NamedExpr<E, Name>

where E: GroupByIdentity,

type Identity = <E as GroupByIdentity>::Identity

impl<E: GroupByIdentity> GroupByIdentity for AliasedExpr<E>

type Identity = <E as GroupByIdentity>::Identity

impl<Name, Output> GroupByIdentity for DerivedField<Name, Output>

where Name: Tag, Output: ProjectionOutput,

type Identity = DerivedField<Name, Output>

impl<V: SQLParam, T, N, A> GroupByIdentity for SQLExpr<'_, V, T, N, A>

where T: DataType, N: Nullability, A: AggregateKind,

type Identity = SQLExpr<'_, V, T, N, A>