Struct FuncCount 

pub struct FuncCount {
    pub arg: Option<Box<Expr>>,
    pub filter: Option<Box<Expr>>,
}

The SQL COUNT aggregate function.

When arg is None, represents COUNT(*) (counts all rows). When arg is Some, counts the number of rows where the argument expression is non-null.

Examples

COUNT(*)                       // arg: None, filter: None
COUNT(column)                  // arg: Some(column), filter: None
COUNT(*) FILTER (WHERE cond)   // arg: None, filter: Some(cond)

Fields

arg: Option<Box<Expr>>

The expression to count. None means COUNT(*).

filter: Option<Box<Expr>>

Optional filter applied before counting.

Trait Implementations

impl Clone for FuncCount

fn clone(&self) -> FuncCount

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for FuncCount

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

Formats the value using the given formatter.

impl From<FuncCount> for Expr

fn from(value: FuncCount) -> Self

Converts to this type from the input type.

impl From<FuncCount> for ExprFunc

fn from(value: FuncCount) -> Self

Converts to this type from the input type.

impl PartialEq for FuncCount

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for FuncCount