1. A method for constructing abstract queries defined by a plurality of logical fields which map to a plurality of physical entities of physical data having a particular physical data representation in a database, the method comprising: receiving user input via a user interface, the input comprising a reference to a model entity definition comprising two or more logical fields each corresponding to a separate physical entity; and based on the model entity definition, selectively adding at least one of the two or more logical fields to an abstract query.