PROC SQL: Beyond the Basics Using SAS®

6.1. Introduction

After a table is defined and populated with data, a column as well as its structure may need modifying. The SQL standard provides Data Definition Language (DDL) statements to permit changes to a table’s structure and its data. In this chapter, you will see examples that add and delete columns, modify column attributes, add and delete indexes, rename tables, and update values in rows of data.