The emergence of Web 2.0 has resulted in a huge amount of heterogeneous data that are contributed by a large number of users, engendering new challenges for data management and query processing. Given that the data are unified from various sources and accessed by numerous users, providing users with a unified mediated schema as data integration is insufficient. On one hand, a deterministic mediated schema restricts users' freedom to express queries in their preferred vocabulary; on the other hand, it is not realistic for users to remember the numerous attribute names that arise from integrating various data sources. As such, a user-oriented data management and query interface is required. In this paper, we propose an out-of-the-box approach that separates users' actions from database operations. This separating layer deals with the challenges from a semantic perspective. It interprets the semantics of each data value through tags that are provided by users, and then inserts the value into the database together with these tags. When querying the database, this layer also serves as a platform for retrieving data by interpreting the semantics of the queried tags from the users. Experiments are conducted to illustrate both the effectiveness and efficiency of our approach.