This paper presents flashWeb, a Computer-Aided Web Engineering (CAWE) tool for the model-driven development of web applications that focus on data management. Present-day web applications, like on-line auction systems or enterprise web portals require comprehensive data access, data processing and data manipulation capabilities. However, existing web application development approaches treat data management operations as second-class citizens. They integrate data operations into existing models or derive them as a by-product of business processes. We argue that data management is an important part of the application logic hence we capture operations with an additional Operation Model. We show that the explicit modeling of operations provides many benefits that distinguish our solution from other approaches. We present the flashWeb development process utilizing a graphical notation for the models in use, a CAWE tool that supports the creation of the graphical models and a code generator that creates ready-to-run web applications.