Hello, I came across the article below and thought this might interest at least some people on this list.
Regards, Arjen ------------------------------------------ Title: Semantic errors in SQL queries: A quite complete list Authors: Brass, S; Goldberg, C Source: JOURNAL OF SYSTEMS AND SOFTWARE 79 (5): 630-644 MAY 2006 Language: English Document Type: Article Author Keywords: databases; SQL; queries; bugs; errors; semantic errors; logical errors; software correctness; *static* *analysis*; teaching; database courses; SQL exams Keywords Plus: PERFORMANCE Abstract: We investigate classes of SQL queries which are syntactically correct, but certainly not intended, no matter for which task the query was written. For instance, queries that are contradictory, i.e. always return the empty set, are obviously not intended. However, current database management systems (DBMS) execute such queries without any warning. In this paper, we give an extensive list of conditions that are strong indications of semantic errors. Of course, questions like the satisfiability are in general undecidable, but a significant subset of SQL queries can actually be checked. We believe that future DBMS will perform such checks and that the generated warnings will help to develop application programs with fewer bugs in less time. (c) 2005 Elsevier Inc. All rights reserved.