A centralized method for defining and enforcing strong-typing among domains in RDBMS or ORDBMS is provided to allow flexible, easy, and quick domain creation, as well as facilitating easy implementation and change control on domains. When an application requests data from the database, one or more domains are first identified in the SQL query. A determination is then made as to whether operators for each domain pair in the SQL query are authorized. A determination is also made as to whether functions in the SQL authorized. If the operators and functions in the SQL are authorized, the initial SQL request is rewritten to include a casting formula for each domain pair operation. The rewritten SQL request is then executed.