This paper investigates the inference problems due to functional dependencies (FD) and multi-valued dependencies (MVD) in a multilevel relational database with element classification schemes. The algorithms presented can greatly improve the data availability. To further deal with the indirect privacy violation, the view-based inference control method is proposed which can eliminate the secure problem brought by multi-view collusions. The theories of splitting views into the view dependency basis are the foundation of future work on the view-based inference control.