Defining object classes to match corresponding specialized data types in a relational database

• US 6,397,203 B1
• Filed: 09/30/1998
• Issued: 05/28/2002
• Est. Priority Date: 09/30/1998
• Status: Expired due to Term

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Hembry, Douglas Michael
• Primary Examiner(s): Breene, John
• Assistant Examiner(s): BLACK, LINH
• Application Number:
  US09/163,505
• Publication Number:
  US 20020046201A1
• Time in Patent Office: 1,336 Days
• Field of Search: 707/103,2,4,8,104,1-10,100-104.1,200-206,500-542 395/161,615,610,600,685 709/226,315 345/355 370/352 703/13,6 702/186 714/20,26 717/5
• US Class Current: 1/1
• CPC Class Codes: G06F 16/284 Relational databases
• CPC Class Codes: G06F 16/289 Object oriented databases
• CPC Class Codes: Y10S 707/99932 Access augmentation or optimizing

Abstract

A method, apparatus, and article of manufacture for defining object classes to match corresponding specialized data types stored in a relational database. An object-oriented application program may create an instance of a class for the purpose of representing data in a relational table that comprise a specialized data type. The attributes and behavior of the specialized data type in the database are preserved, where appropriate, in the corresponding class, and are available to the application program.

Claims

1. A method for accessing a database, comprising the steps of:

(a) defining at least one object class in a memory of a computer to match at least one specialized data type stored in the database, wherein at least one method of the object classes produces similar results as equivalent query language expressions for the specialized data types evaluated by a database manager for the database; and

(b) creating at least one instance of the defined object classes in the memory of the computer to manipulate data retrieved from the database that comprise the specialized data types.

2. The method of claim 1 above, wherein the defining step further comprises the step of defining the object classes within a Component Broker.

3. The method of claim 1 above, wherein the methods are selected from a group comprising object initialization, comparisons, query functions, and manipulation functions.

4. The method of claim 1 above, wherein attributes and methods associated with the specialized data type are preserved in the defined object classes.

5. The method of claim 4 above, wherein the methods emulate semantics of the specialized data types.

6. The method of claim 1 above, wherein a public interface of the defined object classes matches characteristics and usage of the specialized data type in the database.

7. The method of claim 1 above, wherein the specialized data types are selected from a group comprising date, decimal, duration, time, and timestamp.

8. The method of claim 1 above, wherein the defined object classes are selected from a group comprising date class, decimal class, duration class, time class, and timestamp class.

9. The method of claim 8 above, wherein the date class stores a calendar date value.

10. The method of claim 8 above, wherein the decimal class stores a decimal value.

11. The method of claim 8 above, wherein the duration class stores a duration value.

12. The method of claim 8 above, wherein the time class stores a time-of-day value.

13. The method of claim 8 above, wherein the timestamp class stores a timestamp value.

14. A computer-implemented system for accessing a database, comprising:

(a) a processor having a memory; and

(b) one or more instructions, performed by the processor, for defining at least one object class in the memory of the processor to match at least one specialized data type stored in the database, wherein at least one member function of the object classes produces similar results as equivalent query language expressions for the specialized data types evaluated by a database manager for the database, and for creating at least one instance of the defined object classes in the memory of the processor to manipulate data retrieved from the database that comprise the specialized data types.

15. The system of claim 14 above, wherein the instructions for defining further comprise instructions for defining the object classes within a Component Broker.

16. The system of claim 15 above, wherein the member functions are selected from a group comprising object initialization, comparisons, query functions, and manipulation functions.

17. The system of claim 14 above, wherein attributes and member functions associated with the specialized data type are preserved in the defined object classes.

18. The system of claim 17 above, wherein the member functions emulate semantics of the specialized data types.

19. The system of claim 14 above, wherein a public interface of the defined object classes matches characteristics and usage of the specialized data type in the database.

20. The system of claim 14 above, wherein the specialized data types are selected from a group comprising date, decimal, duration, time, and timestamp.

21. The system of claim 14 above, wherein the defined object classes are selected from a group comprising date class, decimal class, duration class, time class, and timestamp class.

22. The system of claim 21 above, wherein the date class stores a calendar date value.

23. The system of claim 21 above, wherein the decimal class stores a decimal value.

24. The system of claim 21 above, wherein the duration class stores a duration value.

25. The system of claim 21 above, wherein the time class stores a time-of-day value.

26. The system of claim 21 above, wherein the timestamp class stores a timestamp value.

27. An article of manufacture comprising a carrier embodying logic for accessing a database, the method comprising the steps of:

(a) defining at least one object class in a memory of a computer to match at least one specialized data type stored in the database, wherein at least one method of the object classes produces similar results as equivalent query language expressions for the specialized data types evaluated by a database manager for the database; and

(b) creating at least one instance of the defined object classes in the memory of the computer to manipulate data retrieved from the database that comprise the specialized data types.

28. The method of claim 27 above, wherein the defining step further comprises the step of defining the object classes within a Component Broker.

29. The method of claim 27 above, wherein the methods are selected from a group comprising object initialization, comparisons, query functions, and manipulation functions.

30. The method of claim 27 above, wherein attributes and methods associated with the specialized data type are preserved in the defined object classes.

31. The method of claim 30 above, wherein the methods emulate semantics of the specialized data types.

32. The method of claim 27 above, wherein a public interface of the defined object classes matches characteristics and usage of the specialized data type in the database.

33. The method of claim 27 above, wherein the specialized data types are selected from a group comprising date, decimal, duration, time, and timestamp.

34. The method of claim 27 above, wherein the defined object classes are selected from a group comprising date class, decimal class, duration class, time class, and timestamp class.

35. The method of claim 34 above, wherein the date class stores a calendar date value.

36. The method of claim 34 above, wherein the decimal class stores a decimal value.

37. The method of claim 34 above, wherein the duration class stores a duration value.

38. The method of claim 34 above, wherein the time class stores a time-of-day value.

39. The method of claim 34 above, wherein the timestamp class stores a timestamp value.