Trait diesel::query_builder::SelectClauseExpression

pub trait SelectClauseExpression<QS> {
    type Selection;
    type SelectClauseSqlType;
}

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

Specialised variant of Expression for select clause types

The difference to the normal Expression trait is the query source (QS) generic type parameter. This allows to access the query source in generic code.

Required Associated Types

type Selection

The expression represented by the given select clause

type SelectClauseSqlType

SQL type of the select clause

Implementors