Abstract: Business information systems have extensive databases that are mainly managed in relational databases. What is often missing are automated procedures to analyze these inventories without major restructuring. Therefore, we extend the relational database schema with a context model for fuzzy classification. Based on this, we develop the fuzzy classification query language, FCQL, which allows fuzzy queries to the extended database schema using linguistic variables and converts them into SQL calls to the database. With this we give the user a data mining tool so that he can start extended queries on his databases based on a predefined fuzzy classification and obtain an improved basis for decision-making.