pub fn sum(expr: Expr) -> Expr {
    Expr::AggregateFunction {
        fun: aggregates::AggregateFunction::Sum,
        args: vec![expr],
    }
}
/// Create an expression to represent the sum() aggregate function
Create an expression to represent the sum() aggregate function
Create an expression to represent the sum () aggregate function
pub fn sum(expr: Expr) -> Expr {
    Expr::AggregateFunction {
        fun: aggregates::AggregateFunction::Sum,
        args: vec![expr],
    }
}
pub fn sum ( expr : Expr ) -> Expr { Expr :: AggregateFunction { fun : aggregates :: AggregateFunction :: Sum , args : vec ! [ expr ] , } }
Create an expression to represent the sum() aggregate function
Create an expression to represent the sum () aggregate function
expr
Expr