Function extract_timeseries_params

nodedb-sql/src/planner/aggregate.rs:127–152

Extract timeseries-specific parameters from GROUP BY (bucket interval, group columns). Returns `(Some(interval_ms), group_columns)` if a `time_bucket()` call is found, or `(None, empty)` otherwise. Non-timeseries engines ignore these values.

(
    raw_group_by: &GroupByExpr,
    select_items: &[ast::SelectItem],
    functions: &FunctionRegistry,
)

/// Returns `(Some(interval_ms), group_columns)` if a `time_bucket()` call is found,
/// or `(None, empty)` otherwise. Non-timeseries engines ignore these values.
fn extract_timeseries_params(
    raw_group_by: &GroupByExpr,
    select_items: &[ast::SelectItem],
    functions: &FunctionRegistry,
) -> Result<(Option<i64>, Vec<String>)> {
    let mut bucket_interval_ms: Option<i64> = None;
    let mut group_columns = Vec::new();

    if let GroupByExpr::Expressions(exprs, _) = raw_group_by {
        for expr in exprs {
            let resolved = resolve_group_by_expr(expr, select_items);
            let check_expr = resolved.unwrap_or(expr);

            if let Some(interval) = try_extract_time_bucket(check_expr, functions)? {
                bucket_interval_ms = Some(interval);
                continue;
            }

            if let ast::Expr::Identifier(ident) = expr {
                group_columns.push(normalize_ident(ident));
            }
        }
    }

    Ok((bucket_interval_ms, group_columns))
}

/// Check if an expression is a time_bucket() call and extract the interval.
fn try_extract_time_bucket(expr: &ast::Expr, functions: &FunctionRegistry) -> Result<Option<i64>> {