Struct Labeled 

pub struct Labeled<K, Inner> { /* private fields */ }

A selected item filed under a LabelKey instead of under its own identity, and rendered with that name as its AS.

Trait Implementations

impl<K, Inner: Clone> Clone for Labeled<K, Inner>

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<K: Spelled, Inner> LookupKey for Labeled<K, Inner>

impl<K: LabelKey, Inner: RowField<Scope, Idx>, Scope, Idx> RowField<Scope, Idx> for Labeled<K, Inner>

A label renames whatever it wraps and changes nothing else, so this is one impl rather than one per selectable: the inner value decides the scope check and the decoded type, the label decides the AS and the row key.

type Value = <Inner as RowField<Scope, Idx>>::Value

type Sql = <Inner as RowField<Scope, Idx>>::Sql

This field’s SQL type: the marker Value has already resolved away to a native Rust type. A single-column subquery (Select::contains) needs this to compare its selected column against an outer expression with expr::Comparable, which a native Value can’t do.

fn item(&self) -> SelectItem

impl<K, Inner> RowKey for Labeled<K, Inner>

type Key = K

impl<K, Inner, Scope, Idx> Selection<Scope, Idx> for Labeled<K, Inner>

where Labeled<K, Inner>: RowField<Scope, Idx>,

type Output = <Labeled<K, Inner> as RowField<Scope, Idx>>::Value

fn items(&self) -> Vec<SelectItem>

impl<K, Inner, Scope, Idx> SelectionPart<Scope, Idx> for Labeled<K, Inner>

where Labeled<K, Inner>: RowField<Scope, Idx>,

type Fields<Tail> = RowCons<<Labeled<K, Inner> as RowKey>::Key, <Labeled<K, Inner> as RowField<Scope, Idx>>::Value, Tail>

fn push_items(&self, out: &mut Vec<SelectItem>)