Each field in a Toql query can individually be selected. However fields must be Option<> for this, otherwise they will always be selected in the SQL statement regardless of the query.

# #![allow(unused_variables)]
#fn main() {
    struct User {
        id: u32,				// Always selected in SQL
        name: Option<String>			// Optional field
        middlename: Option<Option<String>>	// Optional field of nullable column
        #[toql(select_always)]
        middlename: Option<String>  		// Nullable column, always selected in SQL
  }
#}