Saturday, November 26, 2005

Doomed to Repeat History

Detecting Semantic Errors in SQL Queries, for example: "SELECT * FROM EMP WHERE JOB = ’CLERK’ AND JOB = ’MANAGER’". Obviously, JOB cannot be two values - yet you are allowed to express it. This and other examples are queries that are simply wrong and should be detected as such. It seems that this entire area of research exists because it's possible to write semantically incorrect queries in the first place. While the first example above may require something like better feedback at the command line, other examples like HAVING and DISTINCT exist because of the language design. It would be neat to have an SQL interpreter that would prevent these incorrect queries from being submittted (similar to IntelliJ or Word). It also covers solving problems with subqueries (using Skolemization) and Null Values.

From the SQLLint page.
Post a Comment