Method for transforming SQL queries
US6836770B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Aug 9, 2002 |
| Grant date | Dec 28, 2004 |
| Priority date | — |
| Expiry date | May 5, 2023 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S707/99935
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A computer-implemented method for transforming an SQL query having a WHERE clause having nested SELECT expressions. The expression in the WHERE clause being transformed by the iterative application of rules to have ThereExists expressions and associated truth-value expressions. Further transforming the expression to form a truth expression having the IS operator and iteratively applying further rules to translate 3-valued logic to z-valued logic. Carrying out a further transformation to remove NOT expressions from the expression and to remove any ThereExists expressions so as to define an expression in z-valued logic with simplified SELECT expressions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.