Systems, methods, and storage mediums for retrieving data are provided. A data definition information having at least one display item and at least one calculation item for representing an unnormalized data structure contained in a database as a logically normalized data structure is provided. A syntax analysis of a retrieval request from a user is performed according to the data definition information so as to convert the retrieval request into a query statement that is executable by the database. The query statement is executed relative to the database so as to obtain a retrieval result. The obtained retrieval result is edited according to the data definition information so as to generate a final retrieval result corresponding to the retrieval request.