  We describe a framework to support the implementation of web-based systems
intended to manipulate data stored in relational databases. Since the
conceptual model of a relational database is often specified as an
entity-relationship (ER) model, we propose to use the ER model to generate a
complete implementation in the declarative programming language Curry. This
implementation contains operations to create and manipulate entities of the
data model, supports authentication, authorization, session handling, and the
composition of individual operations to user processes. Furthermore, the
implementation ensures the consistency of the database w.r.t. the data
dependencies specified in the ER model, i.e., updates initiated by the user
cannot lead to an inconsistent state of the database. In order to generate a
high-level declarative implementation that can be easily adapted to individual
customer requirements, the framework exploits previous works on declarative
database programming and web user interface construction in Curry.
