Semantic Web is envisioned as semantic description of data and services enabling unambiguous computerized interpretation. Thanks to semantic description, computers can perform demanding tasks such as automation of discovery and access to heterogeneous data sources. Although this is possible with the existing technologies, combination of web services technology, ontologies and generative programming methods makes this simpler and more efficient. This paper presents the model for dynamic generation of web services for data retrieval from heterogeneous data sources using ontologies. Emphasis is on dynamic generation of web services customized to a particular user based on the request defined by ontology. The paper also describes a prototype of the model implementation. Some advantages of our approach over other approaches are also provided.