Solving the Relational Data Access Problem with Data Access Services

The object-relational impedance mismatch problem consists of two sub-issues: language impedance and data structure mismatch. Solution to the first issue is to abstract away the programming language from SQL; to the second issue is to abstract away the object-relational transformation from developer. This paper presents three standardized data access services, query, command and repository, collectively as a preferable solution to relational data access. These services are specified declaratively with SQL and JSON. The hard object-relational transformation is delegated to service engine. This paper also presents a reference implementation of the service engine for service execution. The complexity test proves that this reference service engine is capable of handling highly complex objects up to the 5x5 level on the complexity scale developed in this research.