Oracle PL/SQL Programming: A Developer's Workbook

Chapter 12. Cursor Variables

Cursor variables, first available in PL/SQL Version 2.3, are reference pointers to a cursor’s result set. The main advantage of a cursor variable is that it allows us to easily pass the result of a query among different PL/SQL blocks, such as procedures or functions. This chapter tests your ability to define and use cursor variables in your applications.

Beginner

12-1.	Which of the following statements describe a cursor variable? A SELECT statement whose WHERE clause can be varied each time the query is opened in a PL/SQL program. A pointer to the result set of a cursor (a SELECT statement that has been opened in a PL/SQL program). An explicit cursor declared in the specification of a package.
12-2.	What are the two steps you must take to declare a cursor variable?
12-3.	Which of the following declarations of REF CURSOR types are valid, and which are invalid? TYPE my_type IS REF CURSOR; TYPE empdept_t IS REF CURSOR JOINED emp, dept; TYPE living_wage_t IS REF CURSOR RETURN (SELECT salary FROM employee); TYPE all_orders_cvt IS REF CURSOR RETURN orders%ROWTYPE;
12-4.	Given the following definitions of the table and REF CURSOR: CREATE TABLE environmental_disaster ( company_responsible VARCHAR2(100), occurred_on DATE; ); DECLARE TYPE disasters_cvt IS REF CURSOR RETURN environmental_disaster%ROWTYPE; Which of the declarations of cursor variables are valid, and which are invalid? exxon_valdez disasters_cvt; union_carbide_in_bhopal disasters_cvt%ROWTYPE; love_canal environmental_disaster%ROWTYPE; ...