1. A computer-implemented method for modifying physical data comprising a plurality of physical entities and having a particular physical data representation in a database, the method comprising: receiving a selection of an abstract modification operation; receiving a selection of a model entity definition on which to perform the abstract modification operation, the model entity definition comprising two or more logical fields each corresponding to a separate physical entity in the database, wherein each logical specifies at least one access method that maps the logical field to the separate physical entity storing data in the database corresponding to a respective logical field; based on at least the received selections, generating at least two physical modification statements, each modifying one of the two separate physical entities of the physical data; ordering the at least two physical modification statements; and executing, by operation of one or more computer processors, modification operations according to the physical modification statements, whereby the data is modified.