| Introduction to the SQL Procedure |
Structured Query
Language (SQL) is a standardized, widely used language that retrieves and
updates data in relational tables and databases.
A
relation
is a mathematical concept that is similar to the mathematical concept of a
set. Relations are represented physically as two-dimensional tables that are
arranged in rows and columns. Relational theory was developed by E. F. Codd,
an IBM researcher, and first implemented at IBM in a prototype called System
R. This prototype evolved into commercial IBM products based on SQL. The Structured
Query Language is now in the public domain and is part of many vendors' products.
Copyright © 2008 by SAS Institute Inc., Cary, NC, USA. All rights reserved.
