In a software system the database technology is one of the most important part that stores external information into the permanent storage and process them accordingly. However, the most prime concern of any information system is to protect the data in the persistent storage from any unauthorised access. Sometimes, the database technology is developed in such a way that sensitive information may be leaked directly or indirectly during information processing along with control structure of a software code. In this paper, we propose a dependency graph based approach to identify possible confidentiality leakage of a software code. We design a framework using the semantic based dependency analysis technique. It refines the existing syntax-based dependency graph by removing false alarms and generates more precise dependency information that leads to improved security analysis results.