Lab 9.2 Using Cursor FOR Loops and Nesting Cursors

Lab Objectives

After this Lab, you will be able to:

Use a Cursor FOR Loop

Process Nested Cursors

There is an alternative method of handling cursors. It is called the cursor FOR loop because of the simplified syntax that is used. When using the cursor FOR loop, the process of opening, fetching, and closing is handled implicitly. This makes the blocks much simpler to code and easier to maintain.

The cursor FOR loop specifies a sequence of statements to be repeated once for each row returned by the cursor. Use the cursor FOR loop if you need to FETCH and PROCESS each and every record from a cursor.

FOR EXAMPLE

Assume the existence of a table called log with one column.

 create table table_log        (description VARCHAR2(250)); -- ch09_7a.sql DECLARE    CURSOR c_student IS       SELECT student_id, last_name, first_name         FROM student        WHERE student_id < 110; BEGIN    FOR r_student IN c_student    LOOP       INSERT INTO table_log          VALUES(r_student.last_name);    END LOOP; END;