Struct AggSpec 

pub struct AggSpec {
    pub col: Option<String>,
    pub op: AggOp,
    pub alias: String,
}

One resolved aggregation, ready for SQL emission.

Fields

col: Option<String>

Canonical column name from the schema, or None for COUNT(*).

op: AggOp

alias: String

Output alias (JSON key). Always set after planning.

Implementations

impl AggSpec

pub fn sql_expr(&self) -> Result<String, AppError>

Render the SQL aggregate expression for this spec, e.g. COUNT(*) or SUM("amount"). The column name is quoted via DatasetSchema::quote_ident.

By construction (see QueryRequest::agg_plan) every non-COUNT op carries a resolved column and COUNT may omit one. If that invariant is ever violated this returns AppError::Internal rather than panicking, since the value flows onto a live HTTP path.

Trait Implementations

impl Clone for AggSpec

fn clone(&self) -> AggSpec

Returns a duplicate of the value.

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

Performs copy-assignment from source.