1. A method for retrieving query results, comprising: receiving a first abstract query comprising one or more first logical fields defined by a first data abstraction model comprising a plurality of first logical field definitions mapped to physical fields of a first database in a first device, wherein one or more of the first logical fields definitions associate respective first logical fields to respective concepts of a predefined set of concepts, the concepts being standardized metadata; for each of the one or more first logical fields of the first abstract query, determining whether a second data abstraction model comprises a respective second logical field associated with the respective concept associated with the respective first logical field of the first abstract query, wherein the second data abstraction model comprises a plurality of second logical field definitions mapping the second logical fields to physical fields of a second database in a second device, wherein one or more of the second logical field definitions associate respective second logical fields to respective concepts of the predefined set of concepts; upon determining that the second data abstraction model does not comprise the respective second logical field associated with the respective concept associated with the respective first logical field of the first abstract query, modifying the first abstract query to remove the respective first logical field from the first abstract query; generating a second abstract query based on the first abstract query, wherein the second abstract query comprises one or more of the second logical field definitions of the second data abstraction model; executing the second abstract query to generate results of the modified first abstract query; and modifying the results by including the removed logical field of the first abstract query, and inserting NULL values in the included logical field of the first abstract query.