Book Image

Oracle Advanced PL/SQL Developer Professional Guide

By : Saurabh K. Gupta
Book Image

Oracle Advanced PL/SQL Developer Professional Guide

By: Saurabh K. Gupta

Overview of this book

PL/SQL (Procedural Language/Structured Query Language) is Oracle Corporation's procedural extension language for SQL and the Oracle relational database. Server-side PL/SQL is stored and compiled in the Oracle Database and runs within the Oracle executable. With this guide Oracle developers can work towards accomplishing Oracle 11g Advanced PL/SQL Professional certification, which is the second milestone for developers working at the Associate level. The Oracle Advanced PL/SQL Developer Professional Guide helps you master advanced PL/SQL concepts. Besides the clear and precise explanation on advanced topics, it also contains example code and demonstrations, which gives a sense of application and usage to readers.The book gives a deep insight that will help transform readers from mid-level programmers to professional database developers. It aims to cover the advanced features of PL/SQL for designing and optimizing PL/SQL code.This book starts with an overview of PL/SQL as the programming database language and outlines the benefits and characteristics of the language. The book then covers the advanced features that include PL/SQL code writing using collections, tuning recommendations using result caching, implementing VPD to enforce row level security, and much more. Apart from programming, the book also dives deep into the usage of the development tool SQL Developer, employing best practices in database environments and safeguarding the vulnerable areas in PL/SQL code to avoid code injection.
Table of Contents (22 chapters)
Oracle Advanced PL/SQL Developer Professional Guide
Credits
Foreword
About the Author
Acknowledgement
About the Reviewers
www.PacktPub.com
Preface
Index

Manipulating collection elements


A database column of collection type physically stores the data in the database. As part of data operations, the collection type instance held by a column might get updated. There are two approaches to manipulate the collection instance in the database column:

  • The complete instance can be replaced with a new one

  • The target element can be solely modified

The first approach is feasible when the structure of the collection and the value of other attributes of the instance are known. But it may not be the case every time. However, it has been demonstrated in earlier sections. Therefore, Oracle recommends manipulating the collection element through a PL/SQL program.

Let us demonstrate the collection element update with the following illustration. Check out the latest data in the table TAB_USE_NT_COL:

SQL> SELECT * FROM TAB_USE_NT_COL;

        ID NUM
---------- --------------------------
         1 NUM_NEST_T(10, 12, 3)
         2 NUM_NEST_T(10, 12, 13)

Now, we...