QUERY PATTERN TO ENABLE TYPE FLOW OF ELEMENT TYPES

• US 20080189277A1
• Filed: 02/05/2007
• Published: 08/07/2008
• Est. Priority Date: 02/05/2007
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Zabokritski, Eugueni, Vick, Paul A., Meijer, Henricus Johannes Maria, Silver, Amanda K., Tsingauz, Aleksey V.
• Granted Patent: US 7,805,456 B2
• Time in Patent Office: Days
• US Class Current: 707/6
• CPC Class Codes: G06F 16/2423 Interactive query statement specification based on a database schema
• CPC Class Codes: G06F 16/2438 Embedded query languages

Abstract

The claimed subject matter relates to a formalization of operator patterns that can facilitate type flow of element types between an operator in a first clause of an expression to an operator in a next clause of the expression. The type that flows to, and the operator extant in, the next clause can be combined to infer the element type of the next clause. As such, type-checking, autocompletion and other advantageous features can be accomplished incrementally without the need for a prior full translation of the expression.

Claims

1. A computer-implemented system that employs a query pattern to facilitate type flow of element types between operators in an expression, comprising:

an interface that receives a query expression comprising a first query clause and at least one next query clause, the first query clause includes a first query operator, an element type, T, and a source type, the source type is a queryable type; and

a query operator pattern for the at least one next query clause, the query operator pattern ensures type flow of element types to the at least one next query clause.

2. The system of claim 1, the first query operator is a Cartesian product formation and the element type, T, is an anonymous type that is an aggregation of all control variables in scope with respect to the source type.

3. The system of claim 1, the query operator pattern includes a projection or mapping query operator configured to receive as an argument a function that includes an argument of element type, T, and returns a queryable type with an element type, S.

4. The system of claim 1, the query operator pattern includes a filtering or restriction query operator that is configured to receive as an argument a function that includes an argument of element type, T, and returns a queryable type with element type, T.

5. The system of claim 1, the query operator pattern includes a sorting or ordering query operator that is configured to receive as an argument a function that includes an argument of element type, T, and returns an ordered collection with element type, T.

6. The system of claim 1, the query operator pattern includes a duplicate revmoal query operator that is configured to return a queryable type with element type, T.

7. The system of claim 1, the query operator pattern includes a set query operator that is configured to receive as an argument a collection of element type, T, as the source type and returns a queryable type with element type, T.

8. The system of claim 1, the query operator pattern includes a selection or filtering query operator that is configured to receive as an argument a value and returns a queryable type with element type, T, as the source type.

9. The system of claim 1, the query operator pattern includes a conditional selection or filtering query operator that is configured to receive as an argument a function that includes an argument of element type, T, and returns a queryable type with element type, T.

10. The system of claim 1, the query operator pattern includes an aggregation query operator that is configured to receive as an argument a function that includes an argument of element type, T, and returns a numeric type.

11. The system of claim 1, the query operator pattern includes an aggregation query operator that is configured to receive as an argument a function that includes an argument of element type, T, and returns a queryable type with an element type, S.

12. The system of claim 1, the query operator pattern includes a matching query operator that is configured to receive as an argument a function that includes an argument of element type, T, and returns a type that is implicitly convertible to a Boolean.

13. The system of claim 1, the query operator pattern includes a joining query operator that is configured to receive as an argument a function that includes an argument of element type, T, and an argument of element type, T′

and returns a queryable type with an element type, V, where V is a hash value.

14. The system of claim 1, the query operator pattern includes a nested join query operator that is configured to receive as an argument a function that includes an argument of element type, T, and an argument that is a collection with an element type, U, and returns a queryable type with an element type, V.

15. The system of claim 1, the query operator pattern includes a grouping query operator that is to receive as an argument a function that includes an argument of type, K, where type K is a key, and an argument that is a collection with an element type, T, and returns a queryable type with an element type, V.

16. The system of claim 1, further comprising a context component that infers in real-time an element type based upon the source type and a query operator associated with the at least one next query clause.

17. The system of claim 16, the context component incrementally provides context information based upon the element type inferred.

18. A computer-implemented method for facilitating type flow of element types, comprising:

receiving a portion of a query clause including a query operator associated with a query operator pattern;

utilizing a source type and the query operator for determining an element type; and

employing the element type of a previous query clause as the source type for the act of utilizing.

19. The method of claim 18, further comprising using the query operator pattern for incrementally providing contextual feedback associated with control variables of the element type or the source type.

20. A computer-implemented system for facilitating type flow of element types, comprising:

computer-implemented means for receiving a query operator associated with a query operator pattern;

computer-implemented means for employing the query operator pattern for determining an element type; and

computer-implemented means for using the element type of a previous query clause as a source type for the query operator pattern.