Trait diesel::expression::SelectableExpression

source ·

pub trait SelectableExpression<QS: ?Sized>: AppearsOnTable<QS> { }

Expand description

Indicates that an expression can be selected from a source.

Columns will implement this for their table. Certain special types, like CountStar and Bound will implement this for all sources. Most compound expressions will implement this if each of their parts implement it.

Notably, columns will not implement this trait for the right side of a left join. To select a column or expression using a column from the right side of a left join, you must call .nullable() on it.

Trait diesel::expression::SelectableExpression

Implementations on Foreign Types§

impl<T0, T1, T2, T3, QS> SelectableExpression<QS> for (T0, T1, T2, T3)where T0: SelectableExpression<QS>, T1: SelectableExpression<QS>, T2: SelectableExpression<QS>, T3: SelectableExpression<QS>, (T0, T1, T2, T3): AppearsOnTable<QS>,

impl<T, QS> SelectableExpression<QS> for Box<T>where T: SelectableExpression<QS> + ?Sized, Box<T>: AppearsOnTable<QS>,

impl<T0, QS> SelectableExpression<QS> for (T0,)where T0: SelectableExpression<QS>, (T0,): AppearsOnTable<QS>,

impl<T0, T1, T2, T3, T4, QS> SelectableExpression<QS> for (T0, T1, T2, T3, T4)where T0: SelectableExpression<QS>, T1: SelectableExpression<QS>, T2: SelectableExpression<QS>, T3: SelectableExpression<QS>, T4: SelectableExpression<QS>, (T0, T1, T2, T3, T4): AppearsOnTable<QS>,

impl<T0, T1, T2, QS> SelectableExpression<QS> for (T0, T1, T2)where T0: SelectableExpression<QS>, T1: SelectableExpression<QS>, T2: SelectableExpression<QS>, (T0, T1, T2): AppearsOnTable<QS>,

impl<T0, T1, QS> SelectableExpression<QS> for (T0, T1)where T0: SelectableExpression<QS>, T1: SelectableExpression<QS>, (T0, T1): AppearsOnTable<QS>,

impl<'a, T, QS> SelectableExpression<QS> for &'a Twhere T: SelectableExpression<QS> + ?Sized, &'a T: AppearsOnTable<QS>,

Implementors§

impl<L, R, QS> SelectableExpression<QS> for Concat<L, R>where Concat<L, R>: AppearsOnTable<QS>, L: SelectableExpression<QS>, R: SelectableExpression<QS>,

impl<QS> SelectableExpression<QS> for nowwhere now: AppearsOnTable<QS>,

impl<QS> SelectableExpression<QS> for todaywhere today: AppearsOnTable<QS>,

impl<QS, Query, Value> SelectableExpression<QS> for UncheckedBind<Query, Value>where Self: AppearsOnTable<QS>,

impl<QS, ST, T> SelectableExpression<QS> for SqlLiteral<ST, T>where Self: Expression,

impl<S, C> SelectableExpression<Alias<S>> for AliasedField<S, C>where S: AliasSource, C: Column<Table = S::Target>, Self: AppearsOnTable<Alias<S>>,

impl<ST, I, QS> SelectableExpression<QS> for Many<ST, I>where Many<ST, I>: AppearsOnTable<QS>, ST: SingleValue, I: AsExpression<ST>, <I as AsExpression<ST>>::Expression: SelectableExpression<QS>,

impl<T, QS> SelectableExpression<QS> for Exists<T>where Self: AppearsOnTable<QS>, Subselect<T, Bool>: SelectableExpression<QS>,

impl<T, U, QS> SelectableExpression<QS> for In<T, U>where In<T, U>: AppearsOnTable<QS>, T: SelectableExpression<QS>, U: SelectableExpression<QS>,

impl<T, U, QS> SelectableExpression<QS> for NotIn<T, U>where NotIn<T, U>: AppearsOnTable<QS>, T: SelectableExpression<QS>, U: SelectableExpression<QS>,