PROC SQL: Beyond the Basics Using SAS, Second Edition

Chapter 6: Modifying and Updating Tables and Indexes

Introduction

Modifying Tables

Adding New Columns

Controlling the Position of Columns in a Table

Changing a Column’s Length

Changing a Column’s Format

Changing a Column’s Label

Renaming a Column

Renaming a Table

Indexes

Designing Indexes

Cardinality

Index Selectivity

Defining Indexes

Creating a Simple Index

Creating a Composite Index

Preventing Duplicate Values in an Index

Modifying Columns Containing Indexes

Deleting (Dropping) Indexes

Updating Data in a Table

Summary

 

Introduction

After a table is defined and populated with data, a column as well as its structure might need to be modified. The SQL standard provides Data Definition Language (DDL) statements to permit changes to a table’s structure ...