The simplicity of the relational model types affects Information Systems design. In this paper, we discuss another approach, where the Information System designers would be able to depict the real world in a database model directly. This model provides more powerful and composite data types, as those of the real world. However, more powerful models need query and manipulation languages that can handle the features of the new composite data types. The Conceptual Universal Database Language (CUDL) is such a language that leads to more abstract database design levels. We demonstrate that a database modelled by Entity-Relationship (ER) diagrams can be directly expressed to the CUDL Abstraction Level (CAL), by a set of rules for direct transformation of ER diagrams to CAL. This set consists of 5 rules, proposed in a previous work by us and, in this paper, it is extended with an extra rule that deals with specific situations appearing in practical applications. Consequently, the resulting more powerful and composite data can be directly maintained with the CUDL language. In this way, the development process consisting in conceptual design (ER), transformation to Logical Relational Schema, usage of SQL for data manipulation/retrieval and the reverse steps to present the results in the conceptual level is simplified by conceptual design (ER), transformation to CAL and the usage of CUDL for direct manipulation/retrieval of real world (conceptual) structures.