THE EXTENSION OF RECURSIVE QUERY AND LOGICAL PREDICATE IN SQL

In this paper, we discuss a method to add the function of recursive query and the concept of logic predicate to SoL. In the first part, we give the relation algebra expression of recursive query, and the discussion of syntax and algorithm of two kinds of recursive query: 1. Considering path; 2. Not considering path. In the second part, we give the theory, syntax and algorithm of adding logic predicate to SoL.