System and method for interacting with a persistence layer

• US 20060004855A1
• Filed: 06/07/2004
• Published: 01/05/2006
• Est. Priority Date: 06/07/2004
• Status: Active Grant

• Current Assignee: SAP SE
• Original Assignee: SAP AG (SAP SE)
• Inventors: Debertin, Dirk, Kluger, Gerd, Schweigkoffer, Rainer, Manolov, Svetoslav, Ivanova, Viktoriya
• Granted Patent: US 7,490,102 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 16/2452 Query translation
• CPC Class Codes: G06F 16/972 Access to data in other repository systems, e.g. legacy data or dynamic Web page generation
• CPC Class Codes: Y10S 707/99944 Object-oriented database structure
• CPC Class Codes: Y10S 707/99945 Object-oriented database structure processing

Abstract

A system and method are provided for interacting with a persistence layer. In an embodiment, a persistence layer may receive a representation of Enterprise Java Bean (EJB) metadata. The persistence layer may determine whether the representation of Enterprise Java Bean (EJB) metadata is compatible with a version of the EJB specification. In an embodiment, a representation of an Object-Relational (OR) mapping schema may be generated based, at least in part, on the representation of EJB metadata.

Claims

1. A method comprising:

receiving, at deploy-time, one or more Enterprise Java Bean (EJB) descriptors from an EJB container, the EJB descriptors based, at least in part, on EJB metadata;

determining whether the one or more EJB descriptors are compatible with a version of the EJB specification; and

generating a representation of an Object-Relational (OR) mapping schema based, at least in part, on the EJB descriptors, if the EJB descriptors are compatible with the version of the EJB specification.

2. The method of claim 1, wherein at least one of the EJB descriptors includes an EJB Query Language (EJBQL) persistence request and further comprising:

parsing the EJBQL persistence request to create a tree structure representation of the EJBQL persistence request;

generating a representation of an SQL statement based, at least in part, on the tree structure representation of the EJBQL persistence request; and

providing the representation of the SQL statement to the EJB container.

3. The method of claim 2, further comprising:

determining whether the EJBQL persistence request is compatible with a version of the EJBQL.

4. The method of claim 2, wherein generating the representation of the SQL statement based, at least in part, on the tree structure representation of the EJBQL persistence request comprises one of:

generating a database-independent representation of the SQL statement; and

providing an indicator that the representation of the SQL statement is not database-independent.

5. The method of claim 1, further comprising:

comparing, during startup time, the representation of the OR mapping schema to database catalog information to validate, at least in part, the representation of the OR mapping schema.

6. The method of claim 1, wherein EJB metadata comprises at least one of:

an EJB deployment descriptor;

one or more bean classes of the EJB;

one or more EJB interfaces; and

an OR mapping schema.

7. A method comprising:

generating, during design-time, an in-memory representation of Enterprise Java Bean (EJB) metadata;

determining whether the in-memory representation of EJB metadata is compatible, at least in part, with a version of an EJB specification; and

generating a representation of an Object-Relational (OR) mapping schema based, at least in part, on the in-memory representation of the EJB metadata, if the in-memory representation of the EJB metadata is compatible with the version of the EJB specification.

8. The method of claim 7, further comprising:

comparing, during design-time, the representation of the OR mapping schema to database catalog information to validate, at least in part, the representation of the OR mapping schema.

9. The method of claim 7, further comprising:

determining, during design-time, whether the in-memory representation of EJB metadata complies, at least in part, with an SQL grammar.

10. The method of claim 7, further comprising:

generating, during deploy-time, an EJBQL parser based, at least in part, on the representation of the OR mapping schema.

11. The method of claim 7, further comprising:

generating, during deploy-time, an SQL mapper implementation based, at least in part, on the representation of the OR mapping schema, the SQL mapper implementation to map an EJB persistence request to an SQL statement.

12. The method of claim 11, further comprising:

determining whether the SQL statement is to comply with an SQL grammar; and

determining, at startup time, whether a datasource is compatible with the SQL grammar.

13. The method of claim 7, wherein EJB metadata comprises at least one of:

an EJB deployment descriptor;

one or more bean classes of the EJB;

one or more EJB interfaces; and

an OR mapping schema.

14. An apparatus comprising:

a development environment to access Enterprise Java Bean (EJB) metadata; and

a processor and logic executable thereon to

generate, during design-time, an in-memory representation of the EJB metadata;

determine whether the in-memory representation of the EJB metadata is compatible, at least in part, with a version of an EJB specification; and

generate a representation of an Object-Relational (OR) mapping schema based, at least in part, on the in-memory representation of the EJB metadata, if the in-memory representation of the EJB metadata is compatible with the version of the EJB specification.

15. The apparatus of claim 14, wherein the processor and logic executable thereon further comprises logic to:

compare, during design-time, the representation of the OR mapping schema to database catalog information to validate, at least in part, the representation of the OR mapping schema.

16. The apparatus of claim 14, wherein the processor and logic executable thereon further comprises logic to:

determine, during design-time, whether the in-memory representation of the EJB metadata complies, at least in part, with an SQL grammar.

17. A system comprising:

means for receiving, at deploy-time, one or more Enterprise Java Bean (EJB) descriptors from an EJB container, the EJB descriptors based, at least in part, on EJB metadata;

means for determining whether the one or more EJB descriptors are compatible with a version of the EJB specification; and

means for generating a representation of an Object-Relational (OR) mapping schema based, at least in part, on the EJB descriptors, if the EJB descriptors are compatible with the version of the EJB specification.

18. The system of claim 17, wherein at least one of the EJB descriptors includes an EJB Query Language (EJBQL) persistence request and further comprising:

means for parsing the EJBQL persistence request to create a tree structure representation of the EJBQL persistence request;

means for generating a representation of an SQL statement based, at least in part, on the tree structure representation of the EJBQL persistence request; and

means for providing the representation of the SQL statement to the EJB container.

19. The system of claim 18, further comprising:

means for determining whether the EJBQL persistence request is compatible with a version of the EJBQL.

20. The system of claim 18, wherein the means for generating the representation of the SQL statement based, at least in part, on the tree structure representation of the EJBQL persistence request comprises one of:

means for generating a database-independent representation of the SQL statement; and

means for providing an indicator that the representation of the SQL statement is not database-independent.

21. The system of claim 18, further comprising:

means for comparing, during startup time, the representation of the OR mapping schema to database catalog information to validate, at least in part, the representation of the OR mapping schema.

22. The system of claim 17, further comprising:

means for generating, during deploy-time, an EJBQL parser based, at least in part, on the representation of the OR mapping schema.

23. The system of claim 17, further comprising:

means for generating, during deploy-time, an SQL mapper implementation based, at least in part, on the representation of the OR mapping schema, the SQL mapper implementation to map an EJB persistence request to an SQL statement.

24. The system of claim 23, further comprising:

means for determining whether the SQL statement is to comply with an SQL grammar; and

means for determining, at startup time, whether a datasource is compatible with the SQL grammar.

25. An article of manufacture comprising:

an electronically accessible medium providing instructions that, when executed by an apparatus, cause the apparatus to

generate, during design-time, an in-memory representation of Enterprise Java Bean (EJB) metadata;

determine whether the in-memory representation of EJB metadata is compatible, at least in part, with a version of an EJB specification; and

generate a representation of an Object-Relational (OR) mapping schema based, at least in part, on the in-memory representation of the EJB metadata, if the in-memory representation of the EJB metadata is compatible with the version of the EJB specification.

26. The article of manufacture of claim 25, wherein the electronically accessible medium provides further instructions that, when executed by the apparatus, cause the apparatus to:

compare, during design-time, the representation of the OR mapping schema to database catalog information to validate, at least in part, the representation of the OR mapping schema.

27. The article of manufacture of claim 25, wherein the electronically accessible medium provides further instructions that, when executed by the apparatus, cause the apparatus to:

determine, during design-time, whether the in-memory representation of EJB metadata complies, at least in part, with an SQL grammar.

28. The article of manufacture of claim 25, wherein the electronically accessible medium provides further instructions that, when executed by the apparatus, cause the apparatus to:

generate, during deploy-time, an EJBQL parser based, at least in part, on the representation of the OR mapping schema.

29. The article of manufacture of claim 25, wherein the electronically accessible medium provides further instructions that, when executed by the apparatus, cause the apparatus to:

generate, during deploy-time, an SQL mapper implementation based, at least in part, on the representation of the OR mapping schema, the SQL mapper implementation to map an EJB persistence request to an SQL statement.

30. An article of manufacture comprising:

an electronically accessible medium providing instructions that, when executed by an apparatus, cause the apparatus to;

receive, at deploy-time, one or more Enterprise Java Bean (EJB) descriptors from an EJB container, the EJB descriptors based, at least in part, on EJB metadata;

determine whether the one or more EJB descriptors are compatible with a version of the EJB specification; and

generate a representation of an Object-Relational (OR) mapping schema based, at least in part, on the EJB descriptors, if the EJB descriptors are compatible with the version of the EJB specification.

31. The article of manufacture of claim 30, wherein at least one of the EJB descriptors includes an EJB Query Language (EJBQL) persistence request and the electronically accessible medium provides further instructions that, when executed by the apparatus, cause the apparatus to:

parse the EJBQL persistence request to create a tree structure representation of the EJBQL persistence request;

generate a representation of an SQL statement based, at least in part, on the tree structure representation of the EJBQL persistence request; and

provide the representation of the SQL statement to the EJB container.

32. The article of manufacture of claim 31 wherein the electronically accessible medium provides further instructions that, when executed by the apparatus, cause the apparatus to:

determine whether the EJBQL persistence request is compatible with a version of the EJBQL.

33. The article of manufacture of claim 31, wherein the instructions that, when executed by the apparatus, cause the apparatus to generate the representation of the SQL statement based, at least in part, on the tree structure representation of the EJBQL persistence request cause the apparatus to perform one of the following:

generate a database-independent representation of the SQL statement; and

provide an indicator that the representation of the SQL statement is not database-independent.

34. The article of manufacture of claim 30, wherein the electronically accessible medium provides further instructions that, when executed by the apparatus, cause the apparatus to:

compare, during startup time, the representation of the OR mapping schema to database catalog information to validate, at least in part, the representation of the OR mapping schema.

35. The article of manufacture of claim 30, wherein the electronically accessible medium provides further instructions that, when executed by the apparatus, cause the apparatus to:

generate, during deploy-time, an EJBQL parser based, at least in part, on the representation of the OR mapping schema.

36. The article of manufacture of claim 30, wherein the electronically accessible medium provides further instructions that, when executed by the apparatus, cause the apparatus to:

generate, during deploy-time, an SQL mapper implementation based, at least in part, on the representation of the OR mapping schema, the SQL mapper implementation to map an EJB persistence request to an SQL statement.

37. The article of manufacture of claim 36, wherein the electronically accessible medium provides further instructions that, when executed by the apparatus, cause the apparatus to:

determine whether the SQL statement is to comply with an SQL grammar; and

determine, at startup time, whether a datasource is compatible with the SQL grammar.