Struct PkGroup 

pub struct PkGroup<Table>(/* private fields */);

GROUP BY marker: the group key is Table’s single-column primary key.

The table macros produce this when .group_by(col) is called with a table’s only primary-key column. Every other column of that table depends on its primary key (SQL:1999 functional dependency), so any column of Table may be selected without being listed in GROUP BY. Columns of other tables (for example joined ones) must still be aggregated.

Grouping by the bare primary key also lets the database read groups in key order instead of sorting the whole result, which helps GROUP BY ... ORDER BY pk LIMIT n.

Trait Implementations

impl<Table: Clone> Clone for PkGroup<Table>

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<Table: Copy> Copy for PkGroup<Table>

impl<Table: Debug> Debug for PkGroup<Table>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<Table: Default> Default for PkGroup<Table>

fn default() -> Self

Returns the “default value” for a type.

impl<Scope, Used, Cols, T, Proof> MarkerAggValidFor<PkGroup<T>, Proof> for Scoped<SelectCols<Cols>, Scope, Used>

where Cols: ScalarColumnsIn<PkGroup<T>, Proof>,

impl<Scope, Used, T> MarkerAggValidFor<PkGroup<T>> for Scoped<SelectStar, Scope, Used>

impl<Scope, Used, T> MarkerAggValidFor<PkGroup<T>> for Scoped<SelectExpr, Scope, Used>

impl<Scope, Used, R, T> MarkerAggValidFor<PkGroup<T>> for Scoped<SelectAs<R>, Scope, Used>