Function extract_qualified_column

nodedb-sql/src/planner/subquery.rs:325–338

Extract table.column from a qualified identifier. Returns `None` for schema-qualified references (`schema.table.col`) — those are rejected upstream by `convert_expr` when the expression is fully evaluated.

(expr: &Expr)

/// Returns `None` for schema-qualified references (`schema.table.col`) — those
/// are rejected upstream by `convert_expr` when the expression is fully evaluated.
fn extract_qualified_column(expr: &Expr) -> Option<(String, String)> {
    match expr {
        Expr::CompoundIdentifier(parts) if parts.len() >= 3 => {
            // Schema-qualified: cannot extract table/column sensibly.
            // convert_expr will reject this path with Unsupported.
            None
        }
        Expr::CompoundIdentifier(parts) if parts.len() == 2 => {
            Some((normalize_ident(&parts[0]), normalize_ident(&parts[1])))
        }
        Expr::Identifier(ident) => Some((String::new(), normalize_ident(ident))),
        _ => None,
    }
}

fn is_comparison_op(op: &ast::BinaryOperator) -> bool {
    matches!(