Trait diesel::query_builder::SelectClauseExpression

source ·
pub trait SelectClauseExpression<QS> {
    type Selection;
    type SelectClauseSqlType;
Available on crate feature i-implement-a-third-party-backend-and-opt-into-breaking-changes only.
Expand description

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