SEQUEL

TLDR

SEQUEL identifies simple operations on tabular structures equivalent in power to first‑order predicate calculus without using bound variables or quantifiers. The paper introduces SEQUEL as a structured English query language for accessing relational databases, designed for both professional programmers and occasional users. SEQUEL offers a consistent set of keyword English templates that mirror table usage and lets users compose them into more complex queries.

Abstract

In this paper we present the data manipulation facility for a structured English query language (SEQUEL) which can be used for accessing data in an integrated relational data base. Without resorting to the concepts of bound variables and quantifiers SEQUEL identifies a set of simple operations on tabular structures, which can be shown to be of equivalent power to the first order predicate calculus. A SEQUEL user is presented with a consistent set of keyword English templates which reflect how people use tables to obtain information. Moreover, the SEQUEL user is able to compose these basic templates in a structured manner in order to form more complex queries. SEQUEL is intended as a data base sublanguage for both the professional programmer and the more infrequent data base user.