17. A system, comprising: a processor; and a memory containing a program which, when executed by the processor, performs an operation for determining, from a physical database table having one or more fields and stored in a physical database, a set of query entities for a database abstraction model, comprising: identifying, from actual fields of the physical database table, a selection of an entity field containing a plurality of values, determining a plurality of unique values within the plurality of values for presentation to a user, identifying a user selection of one or more of the unique values from the plurality of unique values generating one or more query entity definitions based on the selected one or more unique values, comprising, for each selected unique value: determining one or more fields of the physical database table for which a plurality of records containing the selected unique value have data values, wherein records in the plurality of records do not have data values for at least one other field of the physical database table, programmatically populating, in a user interface, the determined one or more fields of the physical database table, wherein the user interface includes an indication, for each of the at least one other fields, that the records in the plurality of records do not have data values for the respective other field, receiving, from the user interface, a user selection of one or more additional fields selected from the at least one other field of the physical database table to include in the respective query entity definition, and receiving, from the user interface, a user confirmation to create a query entity definition whereby the query entity definition for the selected unique value is generated and contains the determined one or more fields and the selected additional fields, and storing the generated one or more query entity definitions as one or more objects of the database abstraction model, wherein the database abstraction model logically describes the physical database that includes the physical database table.
17. A system, comprising: a processor; and a memory containing a program which, when executed by the processor, performs an operation for determining, from a physical database table having one or more fields and stored in a physical database, a set of query entities for a database abstraction model, comprising: identifying, from actual fields of the physical database table, a selection of an entity field containing a plurality of values, determining a plurality of unique values within the plurality of values for presentation to a user, identifying a user selection of one or more of the unique values from the plurality of unique values generating one or more query entity definitions based on the selected one or more unique values, comprising, for each selected unique value: determining one or more fields of the physical database table for which a plurality of records containing the selected unique value have data values, wherein records in the plurality of records do not have data values for at least one other field of the physical database table, programmatically populating, in a user interface, the determined one or more fields of the physical database table, wherein the user interface includes an indication, for each of the at least one other fields, that the records in the plurality of records do not have data values for the respective other field, receiving, from the user interface, a user selection of one or more additional fields selected from the at least one other field of the physical database table to include in the respective query entity definition, and receiving, from the user interface, a user confirmation to create a query entity definition whereby the query entity definition for the selected unique value is generated and contains the determined one or more fields and the selected additional fields, and storing the generated one or more query entity definitions as one or more objects of the database abstraction model, wherein the database abstraction model logically describes the physical database that includes the physical database table. 24. The system of claim 17 , wherein generating one or more query entity definitions further comprises: providing, in the user interface, an indication for a first field of the physical database table indicating that some, but not all, of the records in the plurality of records have data values for the first field.