Function ensure_not_set

datafusion/sql/src/parser.rs:310–315

(field: &Option<T>, name: &str)

}

fn ensure_not_set<T>(field: &Option<T>, name: &str) -> Result<(), DataFusionError> {
    if field.is_some() {
        parser_err!(format!("{name} specified more than once",))?
    }
    Ok(())
}

/// DataFusion SQL Parser based on [`sqlparser`]
///