Trait GroupByIdentity 

pub trait GroupByIdentity {
    type Identity;
}

Row inference types and traits. 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> GroupByIdentity for AliasedExpr<E>

where E: GroupByIdentity,

type Identity = <E as GroupByIdentity>::Identity

impl<Lhs, Rhs, Op> GroupByIdentity for ColumnBinOp<Lhs, Rhs, Op>

type Identity = ColumnBinOp<Lhs, Rhs, Op>

impl<T> GroupByIdentity for ColumnNeg<T>

type Identity = ColumnNeg<T>

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

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

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