Object relational mapping layer

• US 20050097187A1
• Filed: 10/10/2003
• Published: 05/05/2005
• Est. Priority Date: 10/10/2003
• Status: Active Grant

• Current Assignee: Oracle International Corporation (Oracle Corporation)
• Original Assignee: Oracle International Corporation (Oracle Corporation)
• Inventors: Thompson, David, Kuntawar, Yogeshwar Wamanrao, Nickolayev, Oleg
• Granted Patent: US 7,599,948 B2
• Time in Patent Office: Days
• US Class Current: 709/217
• CPC Class Codes: G06F 16/252 between a Database Management System and a front-end application
• CPC Class Codes: Y10S 707/99942 Manipulating data structure, e.g. compression, compaction, compilation
• CPC Class Codes: Y10S 707/99943 Generating database or data structure, e.g. via user interface

Abstract

An integration server system for mapping data objects on a database schema offers a strongly-typed model API, complex constraint management, and association balancing. The integration server system also has improved performance through optimized handling of ordered associations of data object and of string-valued attributes. The integration server system comprises a database schema configured to store a set of data object instances. A metadata model represents a configuration of the set of data object instances in the database schema. A model application programming interface provides a client application with access to the set of data object instances, and a metadata application programming interface provides a client application with access to the set of data object instances via the metadata model.

Claims

1. An integration server system comprising:

a database schema configured to store a set of data object instances;

a metadata model representing a configuration of the set of data object instances in the database schema;

a model application programming interface adapted to provide a client application with access to the set of data object instances; and

a metadata application programming interface adapted to provide a client application with access to the set of data object instances via the metadata model.

2. The integration server system of claim 1, wherein the database schema includes a table having a plurality of rows and columns adapted to store the set of data object instances;

and

the metadata model includes a representation of the table.

3. The integration server system of claim 1, wherein the model application programming interface is adapted to access the set of data object instances via the metadata application programming interface.

4. The integration server system of claim 1, wherein the database schema includes a sequence attribute adapted to preserve an ordered association between the set of data object instances, such that an intermediate sequence attribute instance has a random value between a pair of values of a pair of adjacent sequence attribute instances.

5. The integration server system of claim 4, wherein the intermediate sequence attribute instance has a floating point value.

6. The integration server system of claim 1, wherein the database schema is adapted to alternately store an instance of a string-valued attribute of the set of data object in a first data-type or a second data-type in response to the length of the instance of the string-valued attribute.

7. The integration server system of claim 6, wherein the first data-type is a fixed-length data structure having a predetermined size and adapted to store the instance of the string-valued attribute in response to the instance of the string-valued attribute having a length less than the predetermined size, and wherein the second data-type is a variable length data structure adapted to store the instance of the string-valued attribute in response to the instance of the string-valued attribute having a length greater than the predetermined size.

8. The integration server system of claim 7, wherein the model application programming interface is adapted to receive the instance of the string-valued attribute from a client program, to determine the length of the instance of the string-valued attribute, and to direct the instance of the string-valued attribute to either the first data-type or the second data-type in response to the length of the instance of the string-valued attribute.

9. The integration server system of claim 8, wherein the first data-type is associated with a first column of a table of the database schema, and the second data-type is associated with a second column of the table of the database schema.

10. The integration server system of claim 1, wherein the database schema includes a database constraint adapted to ensure that the set of data object instances include a set of valid attribute values.

11. The integration server system of claim 10, wherein the database schema includes a class type attribute identifying each of the set of data object instances as a member of at least one of a plurality of classes.

12. The integration server system of claim 11, wherein the database constraint is conditioned on the value of the class type attribute.

13. The integration server system of claim 10, wherein the database constraint is a “

not null”

constraint.

14. The integration server system of claim 10, wherein the database constraint is an “

arc”

constraint.

15. The integration server system of claim 1, wherein the model application programming interface includes an association balance method adapted to balance an association attribute of the set of data object instances.

16. The integration server system of claim 1, further including a generator adapted to create the database schema in response to a model description.

17. The integration server system of claim 16, wherein the model description defines a data object hierarchy using the unified modeling language.

18. The integration server system of claim 16, wherein the generator creates an instance of a data object in the database schema.

19. The integration server system of claim 16, wherein the generator creates a database constraint adapted to ensure that the set of data object instances include a set of valid attribute values.

20. The integration server system of claim 16, wherein the generator creates a fixed-length data structure having a predetermined size and a variable length data structure adapted to alternately store an instance of a string-valued attribute.

21. A method of creating an ordered association between an intermediate data object instance and a pair of adjacent data object instances, the method comprising:

adding the intermediate data object instance to a database schema;

retrieving a pair of sequence attribute values from the pair of adjacent data object instances; and

determining an intermediate sequence attribute value for the intermediate data object instance, wherein the intermediate sequence attribute value includes a random portion.

22. The method of claim 21, wherein the intermediate sequence attribute value includes a portion halfway between the pair of adjacent sequence attribute values.

23. The method of claim 21, wherein the intermediate sequence attribute value is a floating point number.

24. A method of storing a string attribute in a database schema, the method comprising:

receiving a string attribute value from a client application;

determining the length of the string attribute value; and

storing the string attribute value in a fixed-length data structure having a predetermined size in response to the length being less than the predetermined size and storing the string attribute in a variable length data structure in response to the length being greater than the predetermined size.