Skip to Main Content
Oracle PL/SQL Programming: A Developer's Workbook
book

Oracle PL/SQL Programming: A Developer's Workbook

by Steven Feuerstein, Andrew Odewahn
May 2000
Intermediate to advanced content levelIntermediate to advanced
594 pages
11h 32m
English
O'Reilly Media, Inc.
Content preview from Oracle PL/SQL Programming: A Developer's Workbook

Intermediate

Q:

2-7.

A REPEAT UNTIL loop executes its body and then checks to see if the condition for stopping execution is TRUE. You can implement a REPEAT UNTIL loop with the simple loop as follows:

LOOP
   ...
   EXIT WHEN <condition>;
END LOOP;

Q:

2-8.

This loop does not execute even once. When you use the REVERSE keyword, the year_index moves from highest to lowest value (the reverse of the normal order). However, the low value of the range must still be first, as shown here:

FOR year_index IN REVERSE 1990 .. 1999
LOOP
   calc_sales (year_index);
END LOOP;

Q:

2-9.

At first glance, you might think that a FOR loop would make the most sense (“for each…”). A FOR loop would be a mistake in this context, however, because there is also a conditional exit (under certain conditions, stop after 12 years). You should use a FOR loop only when you are going to iterate unconditionally through every value between the low- and high-range limits. Instead, use a simple or WHILE loop to satisfy this requirement.

Q:

2-10.

Since there is no conditional exit described in this requirement, you should use the cursor FOR loop.

Q:

2-11.

Use the WHILE loop, since there are conditions under which you do not want the loop body to execute even a single time.

Q:

2-12.

Do not use a generic loop index name (i); it makes the code less readable, and it looks unprofessional. In addition, the conditional EXIT from the FOR loop should be removed. Instead, use a FOR loop that iterates as follows:

FOR i IN 1 .. LEAST (76, total_count) LOOP ...
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Start your free trial

You might also like

Oracle Database 12c PL/SQL Programming

Oracle Database 12c PL/SQL Programming

Michael McLaughlin
Oracle PL/SQL for DBAs

Oracle PL/SQL for DBAs

Arup Nanda, Steven Feuerstein
Oracle PL/SQL For Dummies

Oracle PL/SQL For Dummies

Michael Rosenblum, Paul Dorsey

Publisher Resources

ISBN: 9781449324070Supplemental ContentErrata Page