12. A method of managing relationships between program code files in an integrated development environment executed on a computer, comprising: modifying a relational schema according to a change in one of the program code files, the relational schema comprising at least two related tables with symbols from the program code files based on a framework for models in the integrated development environment, wherein the change is one of “add”, “remove” and “update”, and wherein the at least two related tables comprise a public symbols table and a referenced symbols table; determining a relationship between the at least two related tables in the relational schema; modifying a definition set according to the change to include definitions from the changed program code file for symbols therefrom in the relational schema into the definition set, the definition set retaining symbol definitions for the program code files; and producing proxy definitions for use with the definition set for each symbol in the changed program code file without a definition in the definition set.
12. A method of managing relationships between program code files in an integrated development environment executed on a computer, comprising: modifying a relational schema according to a change in one of the program code files, the relational schema comprising at least two related tables with symbols from the program code files based on a framework for models in the integrated development environment, wherein the change is one of “add”, “remove” and “update”, and wherein the at least two related tables comprise a public symbols table and a referenced symbols table; determining a relationship between the at least two related tables in the relational schema; modifying a definition set according to the change to include definitions from the changed program code file for symbols therefrom in the relational schema into the definition set, the definition set retaining symbol definitions for the program code files; and producing proxy definitions for use with the definition set for each symbol in the changed program code file without a definition in the definition set. 21. The method according to claim 12 wherein the changed program code file contains public symbols having a definition in the changed program code file and referenced symbols only being referred to in the changed program code file wherein the step of producing proxy definitions comprises: determining if the definition set contains a definition for the referenced symbols; parsing the changed program code file to extract information about the referenced symbols from the changed program code file; formulating a proxy definition for the referenced symbols without a definition in the definition set based on the extracted information; and adding the formulated proxy definition to one of the definition set or the changed program code file.