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Lab 18.1 Exercises
18.1.1 Use Index-By Tables
In this exercise, you will learn more about index-by tables discussed earlier in the chapter.Create the following PL/SQL script:
-- ch18_1a.sql, version 1.0
SET SERVEROUTPUT ON
DECLARE
CURSOR course_cur IS
SELECT description
FROM course;
TYPE course_type IS TABLE OF course.description%TYPE
INDEX BY BINARY_INTEGER;
course_tab course_type;
v_counter INTEGER := 0;
BEGIN
FOR course_rec IN course_cur LOOP
v_counter := v_counter + 1;
course_tab(v_counter) := course_rec.description;
END LOOP;
END;
Answer the following questions:
| a) | Explain the script ch18_1a.sql. |
| b) | Modify the script so that rows of the index-by table are displayed on the screen. |
| c) | Modify the script so that only first and last rows of the index-by table are displayed on the screen. |
| d) | Modify the script by adding the following statements and explain the output produced:
|
18.1.2 Use Nested Tables
In this exercise, you will learn more about nested tables discussed earlier in this chapter.Answer the following questions:
| a) | Modify the script 18_1a.sql used in |
| b) | Modify the script by adding the following statements and explain the output produced:
|
| c) | How would you modify the script created, so that there is no error generated when a new value is assigned to the trimmed element? |
