Path expressions and SQL select statement in object oriented language

• US 20040193575A1
• Filed: 03/25/2003
• Published: 09/30/2004
• Est. Priority Date: 03/25/2003
• Status: Abandoned Application

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Inventors: Schulte, Wolfram, Warren, Matthew J., Chen, Chia-Hsun, Venter, Barend H., Meijer, Erik, Lovett, Christopher J.
• Application Number:
  US10/396,866
• Publication Number:
  US 20040193575A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 16/289 Object oriented databases

Abstract

An object-oriented programming language with integrated query powers for both SQL and XML is disclosed. Portions of SQL select statement as well as XPath have been tightly integrated into a compiler and type system to provide for strongly typed programming and seamless access to both SQL and XML data.

Claims

1. A system for querying data comprising:

a component that accesses a database; and

a query expression specified in an object-oriented programming language, wherein execution of the query expression retrieves data in accordance with the query expression.

2. The system of claim 1, wherein the query expression is executed in a multi-language runtime environment.

3. The system of claim 1, wherein the query expression is strongly-typed and integrated into the type system and compiler of the object-oriented language.

4. The system of claim 3, wherein the query expression corresponds to a SQL select statement.

5. The system of claim 3, wherein the query expression corresponds to an XPath expression.

6. The system of claim 1, wherein the database contains XML documents.

7. The system of claim 1, wherein the database is a relational database.

28. A computer readable medium having stored thereon the system of claim 1.

31. A data packet that passes between at least two computer processes comprising the system of claim 1.

8. A system for retrieving data comprising:

a component that accesses a relational database comprising one or more tables of data, and its associated database management system; and

a query expression specified in a strongly typed object oriented language, wherein data is retrieved in the fonn of a result set from the relational database after requesting data using the query expression.

9. The system of claim 8, wherein the query expression corresponds to a SQL select statement.

10. The system of claim 9, wherein the select statement contains a join operator employed to specify a join operation on two tables of data

11. The system of claim 10, wherein the join operation is an inner join.

12. The system of claim 10, wherein the join operation is a left outer join.

13. The system of claim 10, wherein the join operation is a right outer join.

14. The system of claim 10, wherein the join operation is a full outerjoin.

15. The system of claim 9, wherein the select statement contains a with-clause to specify hints.

16. The system of claim 9, wherein the select statement includes a top keyword for limiting the number of rows returned in the result.

17. The system of claim 9, wherein the result set is a stream.

18. The system of claim 17, wherein the select statement includes a singleton keyword to strongly type the result set to be one row and not a stream when there is only one row in the result set.

19. The system of claim 17, wherein the “

distinct”

keyword is incorporated into the select statement to remove duplicates in the result set.

20. The system of claim 17, wherein an orderby-clause is incorporated into the select statement to order the elements of the result set.

21. The system of claim 17, wherein an groupby-clause is incorporated into the select statement to produce aggregate values for each row in the result set

22. A system for retrieving data comprising:

a path expression specified in an object-oriented programming language; and

a component that receives data from an XML document via executing the path expression on the XML document such that the data is in the form of a result set from the XML document.

23. The system of claim 22, wherein the path expression is integrated into a compiler and type system of the object-oriented programming language.

24. The system of claim 22, wherein the result set is a stream of values.

25. The system of claim 24, wherein the result set is grouped according to criteria specified in the path expression.

26. A method for ensuring a valid query expression comprising:

specifying a query expression in an strongly typed object-oriented programming language;

compiling the query expression using the same compiler employed to compile an entire program; and

producing errors for invalid syntax and types.

27. The method of claim 26, further comprising suggesting changes to help a programmer fix the produced errors.

29. A computer readable medium having stored thereon computer executable instructions for carrying out the method of claim 26.

30. A system for ensuring a valid query expression comprising:

means for specifying a query expression in an strongly typed object-oriented programming language;

means for compiling the query expression using the same compiler employed to compile an entire program; and

means for producing errors for invalid syntax and types.

32. A method of retrieving XML data comprising:

specifying a path expression within a program of a strongly typed object-oriented programming language;

executing the path on an XML document; and

producing a result set.

33. A method for retrieving relational data comprising:

specifying a SQL select statement within a program of a strongly typed object oriented programming language;

executing the statement on relational data in a database; and

producing a result set.