Oracle PL/SQL Programming: A Developer's Workbook

Chapter 14. Procedures, Functions, and Blocks

Procedures and functions are the heart and soul of most PL/SQL programs. A procedure is a named group of instructions—a block—that performs a specific task. A function is similar in structure to a procedure, but it returns a value (called, fittingly enough, a return value) to the block that called it. Both procedures and functions are examples of named blocks; you can also create unnamed—or anonymous—blocks of instructions.

The term “block” is a very apt description, since these groups of instructions literally form the building blocks you can use—and reuse—to create sophisticated applications. This chapter tests your ability to create a procedure or function, define parameters, and analyze a function’s design.

Beginner

14-1.	What is the difference between a procedure and function?
14-2.	What are the four sections in a procedure or function? Which of these sections are optional, and which are required?
14-3.	What statement do you use to return a value from within a function? Can you use this same statement in a procedure?
14-4.	Write a procedure that displays “hello world!” on your monitor.
14-5.	Write a function that returns the string “hello world!”
14-6.	How many RETURNs can you place in your function?
14-7.	Which of the following function headers are valid, and which cause compile errors? FUNCTION deptname (id_in IN department.department_id%TYPE) RETURN VARCHAR2 FUNCTION deptname (id_in IN NUMBER) RETURN VARCHAR2(100) FUNCTION 2topsellers (for_this_dept ...