Sensor networks are promising in many applications; however, we have not yet seen its wide acceptance and deployment. We envision that a big obstacle to solving this dilemma is the lack of an easily usable tool for applications scientists to manage and use sensor networks. In this paper, we take an initial step to tackle this problem by developing a general tool to fill the gap between applications and sensor network protocols, which would also pave the way for the wide acceptance and deployment of sensor networks. Our approach includes two components: a general network programming interface abstracted from common usage patterns, and a transparent query to interface converter which will ease the burden on application scientists significantly. Using this automatic converter, application scientists need to use a high level SQL-like language for plugging and playing wireless sensor network operations. These two components will be integrated and implemented into a general query processing tool called QueryAgent. This tool also maps efficient sensor network protocols to different requirements of end-users in an intelligent way.