Evaluating a traditional database query against a data tuple returns a true on match and a false on mismatch. Unfortunately, there are many application scenarios where such an evaluation is not possible or does not adequately meet users needs. A further problematic application area is text retrieval where in general finding a complete match is impossible. Thus, there is a need for incorporating impreciseness and proximity into a logic-based query language: Objects fulfill such a similarity condition to a certain degree which is expressed by a result value out of the interval [0, 1]. In this work we will sketch a quantum logic-based approach, which provides the combination of classical Boolean predicates and similarity conditions into one integrating formalism.