Oracle PL/SQL by Example

This integrated learning solution teaches all the Oracle PL/SQL skills you need, hands-on, through real-world labs, extensive examples, exercises, and projects! Completely updated for Oracle 11g, Oracle PL/SQL by Example, Fourth Edition covers all the fundamentals, from PL/SQL syntax and program control through packages and Oracle 11g's significantly improved triggers. One step at a time, you'll walk through every key task, discovering the most important PL/SQL programming techniques on your own. Building on your hands-on learning, the authors share solutions that offer deeper insights and proven best practices. End-of-chapter projects bring together all the techniques you've learned, strengthening your understanding through real-world practice. This book's approach fully reflects the authors' award-winning experience teaching PL/SQL programming to professionals at Columbia University. New database developers and DBAs can use its step-by-step instructions to get productive fast; experienced PL/SQL programmers can use this book as a practical solutions reference. Coverage includes * Mastering basic PL/SQL concepts and general programming language fundamentals, and understanding SQL's role in PL/SQL * Using conditional and iterative program control techniques, including the new CONTINUE and CONTINUE WHEN statements * Efficiently handling errors and exceptions * Working with cursors and triggers, including Oracle 11g's powerful new compound triggers * Using stored procedures, functions, and packages to write modular code that other programs can execute * Working with collections, object-relational features, native dynamic SQL, bulk SQL, and other advanced PL/SQL capabilities * Handy reference appendices: PL/SQL formatting guide, sample database schema, ANSI SQL standards reference, and more Benjamin Rosenzweig is a Software Development Manager at Misys. Previously he was a Principal Consultant at Oracle. His experience ranges from creating an electronic Tibetan-English Dictionary in Kathmandu, Nepal, to supporting presentation centers at Goldman Sachs and managing trading systems at TIAA-CREF. As an instructor at Columbia University's Computer Technology and Application Program, he was awarded the Outstanding Teaching Award. Rosenzweig wrote and presented Oracle Forms Developer: The Complete Video Course, and coauthored Oracle Web Application Programming for PL/SQL Developers. Elena Silvestrova Rakhimov is Senior Developer and Team Lead at Alea Software. She has more than fifteen years of experience in database development in a wide spectrum of enterprise and business environments, ranging from non-profit organizations to Wall Street. She has taught database programming at Columbia University. Contents Acknowledgments xiv About the Authors xv Introduction xvii CHAPTER 1 PL/SQL Concepts 1 LAB 1.1 PL/SQL in Client/Server Architecture 2 1.1.1 Use PL/SQL Anonymous Blocks 8 1.1.2 Understand How PL/SQL Gets Executed 10 LAB 1.2 PL/SQL in SQL*Plus 12 1.2.1 Use Substitution Variables 16 1.2.2 Use the DBMS_OUTPUT.PUT_LINE Statement 17 Chapter 1 Try It Yourself 19 CHAPTER 2 General Programming Language Fundamentals 21 LAB 2.1 PL/SQL Programming Fundamentals 22 2.1.1 Make Use of PL/SQL Language Components 23 2.1.2 Make Use of PL/SQL Variables 24 2.1.3 Handle PL/SQL Reserved Words 26 2.1.4 Make Use of Identifiers in PL/SQL 27 2.1.5 Make Use of Anchored Datatypes 28 2.1.6 Declare and Initialize Variables 31 2.1. 7 Understand the Scope of a Block, Nested Blocks, and Labels 34 Chapter 2 Try It Yourself 37 CHAPTER 3 SQL in PL/SQL 39 LAB 3.1 Making Use of DML in PL/SQL 40 3.1.1 Use the Select INTO Syntax for Variable Initialization 41 3.1.2 Use DML in a PL/SQL Block 42 3.1.3 Make Use of a Sequence in a PL/SQL Block 44 LAB 3.2 Making Use of SAVEPOINT 45 3.2.1 Make Use of COMMIT, ROLLBACK, and SAVEPOINT in a PL/SQL Block 48 Chapter 3 Try It Yourself 51 CHAPTER 4 Conditional Control: IF Statements 53 LAB 4.1 IF Statements 54 4.1.1 Use the IF-THEN Statement 58 4.1.2 Use the IF-THEN-ELSE Statement 62 LAB 4.2 ELSIF Statements 65 4.2.1 Use the ELSIF Statement 69 LAB 4.3 Nested IF Statements 74 4.3.1 Use Nested IF Statements 76 Chapter 4 Try It Yourself 80 CHAPTER 5 Conditional Control: CASE Statements 81 LAB 5.1 CASE Statements 82 5.1.1 Use the CASE Statement 89 5.1.2 Use the Searched CASE Statement 91 LAB 5.2 CASE Expressions 96 5.2.1 Use the CASE Expression 100 LAB 5.3 NULLIF and COALESCE Functions 103 5.3.1 The NULLIF Function 107 5.3.2 Use the COALESCE Function 109 Chapter 5 Try It Yourself 112 CHAPTER 6 Iterative Control: Part I 113 LAB 6.1 Simple Loops 114 6.1.1 Use Simple Loops with EXIT Conditions 118 6.1.2 Use Simple Loops with EXIT WHEN Conditions 120 LAB 6.2 WHILE Loops 124 6.2.1 Use WHILE Loops 128 LAB 6.3 Numeric FOR Loops 132 6.3.1 Use Numeric FOR Loops with the IN Option 137 6.3.2 Use Numeric FOR Loops with the REVERSE Option 139 Chapter 6 Try It Yourself 142 CHAPTER 7 Iterative Control: Part II 143 LAB 7.1 The CONTINUE Statement 144 7.1.1 Use the CONTINUE Statement 146 7.1.2 Use the CONTINUE WHEN Condition 152 LAB 7.2 Nested Loops 154 7.2.1 Use Nested Loops 157 Chapter 7 Try It Yourself 161 CHAPTER 8 Error Handling and Built-in Exceptions 163 LAB 8.1 Handling Errors 164 8.1.1 Understand the Importance of Error Handling 167 LAB 8.2 Built-in Exceptions 169 8.2.1 Use Built-in Exceptions 174 Chapter 8 Try It Yourself 178 CHAPTER 9 Exceptions 179 LAB 9.1 Exception Scope 180 9.1.1 Understand the Scope of an Exception 183 LAB 9.2 User-Defined Exceptions 188 9.2.1 Use User-Defined Exceptions 193 LAB 9.3 Exception Propagation 197 9.3.1 Understand How Exceptions Propagate 203 9.3.2 Reraise Exceptions 206 Chapter 9 Try It Yourself 209 CHAPTER 10 Exceptions: Advanced Concepts 211 LAB 10.1 RAISE_APPLICATION_ERROR 212 10.1.1 Use RAISE_APPLICATION_ERROR 215 LAB 10.2 EXCEPTION_INIT Pragma 217 10.2.1 USE the EXCEPTION_INIT Pragma 219 LAB 10.3 SQLCODE and SQLERRM 222 10.3.1 Use SQLCODE and SQLERRM 225 Chapter 10 Try It Yourself 227 CHAPTER 11 Introduction to Cursors 229 LAB 11.1 Cursor Manipulation 230 11.1.1 Make Use of Record Types 234 11.1.2 Process an Explicit Cursor 235 11.1.3 Make Use of Cursor Attributes 240 11.1.4 Put It All Together 242 LAB 11.2 Using Cursor FOR Loops and Nested Cursors 246 11.2.1 Use a Cursor FOR Loop 247 11.2.2 Process Nested Cursors 247 Chapter 11 Try It Yourself 252 CHAPTER 12 Advanced Cursors 253 LAB 12.1 Using Parameters with Cursors and Complex Nested Cursors 254 12.1.1 Use Parameters in a Cursor 255 12.1.2 Use Complex Nested Cursors 255 LAB 12.2 FOR UPDATE and WHERE CURRENT Cursors 258 12.2.1 For UPDATE and WHERE CURRENT Cursors 258 CHAPTER 13 Triggers 263 LAB 13.1 What Triggers Are 264 13.1.1 Understand What a Trigger Is 272 13.1.2 Use BEFORE and AFTER Triggers 274 LAB 13.2 Types of Triggers 277 13.2.1 Use Row and Statement Triggers 283 13.2.2 Use INSTEAD OF Triggers 285 Chaper 13 Try It Yourself 290 CHAPTER 14 Compound Triggers 291 LAB 14.1 Mutating Table Issues 292 14.1.1 Understand Mutating Tables 296 LAB 14.2 Compound Triggers 300 14.2.1 Understand Compound Triggers 306 Chapter 14 Try It Yourself 313 CHAPTER 15 Collections 315 LAB 15.1 PL/SQL Tables 316 15.1.1 Use Associative Arrays 326 15.1.2 Use Nested Tables 330 LAB 15.2 Varrays 334 15.2.1 Use Varrays 338 LAB 15.3 Multilevel Collections 342 15.3.1 Use Multilevel Collections 344 Chapter 15 Try It Yourself 348 CHAPTER 16 Records 349 LAB 16.1 Record Types 350 16.1.1 Use Table-Based and Cursor-Based Records 358 16.1.2 Use User-Defined Records 362 LAB 16.2 Nested Records 367 16.2.1 Use Nested Records 369 LAB 16.3 Collections of Records 373 16.3.1 Use Collections of Records 374 Chapter 16 Try It Yourself 378 CHAPTER 17 Native Dynamic SQL 379 LAB 17.1 EXECUTE IMMEDIATE Statements 380 17.1.1 Use the EXECUTE IMMEDIATE Statement 387 LAB 17.2 OPEN-FOR, FETCH, and CLOSE Statements 392 17.2.1 Use OPEN-FOR, FETCH, and CLOSE Statements 395 Chapter 17 Try It Yourself 401 CHAPTER 18 Bulk SQL 403 LAB 18.1 The FORALL Statement 404 18.1.1 Use the FORALL Statement 413 LAB 18.2 The BULK COLLECT Clause 422 18.2.1 Use the BULK COLLECT Statement 428 Chapter 18 Try It Yourself 437 CHAPTER 19 Procedures 439 LAB 19.1 Creating Procedures 441 19.1.1 Create Procedures 441 19.1.2 Query the Data Dictionary for Information on Procedures 443 LAB 19.2 Passing Parameters into and out of Procedures 444 19.2.1 Use IN and OUT Parameters with Procedures 445 Chapter 19 Try It Yourself 447 Part 1 447 Part 2 447 CHAPTER 20 Functions 449 LAB 20.1 Creating and Using Functions 450 20.1.1 Create Stored Functions 451 20.1.2 Make Use of Functions 452 20.1.3 Invoke Functions in SQL Statements 453 20.1.4 Write Complex Functions 454 Chapter 20 Try It Yourself 455 CHAPTER 21 Packages 457 LAB 21.1 The Benefits of Using Packages 458 21.1.1 Create Package Specifications 460 21.1.2 Create Package Bodies 462 21.1.3 Call Stored Packages 464 21.1.4 Create Private Objects 465 21.1.5 Create Package Variables and Cursors 469 LAB 21.2 Cursor Variables 471 21.2.1 Make Use of Cursor Variables 475 LAB 21.3 Extending the Package 480 21.3.1 Extend the Package 480 Chapter 21 Try It Yourself 493 CHAPTER 22 Stored Code 495 LAB 22.1 Gathering Information About Stored Code 496 22.1.1 Get Stored Code Information from the Data Dictionary 496 22.1.2 Enforce the Purity Level with the RESTRICT_REFERENCES Pragma 500 22.1.3 Overload Modules 506 Chapter 22 Try It Yourself 512 CHAPTER 23 Object Types in Oracle 513 LAB 23.1 Object Types 514 23.1.1 Use Object Types 522 23.1.2 Use Object Types with Collections 526 LAB 23.2 Object Type Methods 531 23.2.1 Use Object Type Methods 544 Chapter 23 Try It Yourself 554 CHAPTER 24 Oracle Supplied Packages 555 LAB 24.1 Making Use of Oracle Supplied Packages to Profile PL/SQL, Access Files, and Schedule Jobs 556 24.1.1 Access Files with UTL_FILE 563 24.1.2 Schedule Jobs with DBMS_JOB 563 24.1.3 Submit Jobs 564 LAB 24.2 Making Use of Oracle-Supplied Packages to Generate an Explain Plan and Create HTML Pages 568 24.2.1 Generate an Explain Plan with DBMS_XPLAN 572 LAB 24.3 Creating Web Pages with the Oracle Web Toolkit 578 24.3.1 Create an HTML Page with the Oracle Web Toolkit 594 APPENDIX A PL/SQL Formatting Guide 597 APPENDIX B Student Database Schema 601 APPENDIX C ANSI SQL Standards 607 APPENDIX D Answers to the Try It Yourself Sections 613 INDEX 705