Enum ApplicationFunctionKind 

pub enum ApplicationFunctionKind {
    Scalar,
    Aggregate,
    Window,
}

Kind of application-defined function selected for one SQL call.

Application registrations share one namespace across scalar, aggregate, and window functions. A window registration is also callable through the ordinary aggregate form, but remains distinguishable here so callers can validate whether an OVER clause is legal.

Variants

Scalar

A scalar function evaluated once per input row.

Aggregate

An ordinary aggregate function evaluated once per group.

Window

A window function, callable both as an aggregate and with OVER.

Implementations

impl ApplicationFunctionKind

pub const fn label(self) -> &'static str

Lowercase SQL-facing label used in misuse diagnostics.

pub const fn is_aggregate_callable(self) -> bool

Whether the selected registration has an ordinary aggregate call form.

pub const fn is_window_callable(self) -> bool

Whether the selected registration may be used with OVER.

Trait Implementations

impl Clone for ApplicationFunctionKind

fn clone(&self) -> ApplicationFunctionKind

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for ApplicationFunctionKind

impl Debug for ApplicationFunctionKind

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

Formats the value using the given formatter.

impl Eq for ApplicationFunctionKind

impl Hash for ApplicationFunctionKind

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Ord for ApplicationFunctionKind

fn cmp(&self, other: &ApplicationFunctionKind) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl PartialEq for ApplicationFunctionKind

fn eq(&self, other: &ApplicationFunctionKind) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl PartialOrd for ApplicationFunctionKind

fn partial_cmp(&self, other: &ApplicationFunctionKind) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl StructuralPartialEq for ApplicationFunctionKind