In this paper, an approach for refining B abstract specifications describing data-intensive applications into relational database implementations is presented. Using the refinement process of the B method, a set of generic refinement rules are described that take into account both data and operations. The last step consists of mapping the final refined component into a relational database implementation. The different rules have been checked with the AtelierB prover. The aim of the work is to automate the refinement steps. This is possible thanks to the genericity feature of the rules. The approach is illustrated through a running example.