Oracle SQLPlus [Electronic resources] : The Definitive Guide, 2nd Edition نسخه متنی

8.9 Scripting Issues with iSQL*Plus

Using i SQL*Plus, you can execute your scripts
via its browser interface. However, there are differences between
command-line SQL*Plus and browser-based SQL*Plus, and not all scripts
can be made to execute in both environments.

One issue that you encounter is spool files. Browser-based SQL*Plus
runs on an application server. For reasons of security,
i SQL*Plus doesn't allow you to
write files to that server. Thus, you cannot spool output. After all,
i SQL*Plus can hardly spool output through your
browser to a file on your PC. The only way to capture output is to
copy and paste it from your browser window to a file, and
that's only feasible for small amounts of data.

Copying i SQL*Plus output from a browser window and pasting it into another application works best after you issue SET MARKUP HTML ON PREFORMAT ON. Otherwise, you'll be trying to copy an HTML table rather than the output that you desire.

Another problem you'll encounter when executing
scripts from i SQL*Plus is that many SQL*Plus
commands are not supported by i SQL*Plus. These
include commands such as HOST that would present a security risk by
letting you access the application server at the operating system
level, and commands such as EDIT that don't apply in
a browser-based environment.

The EDIT command isn't implemented in i SQL*Plus because your script is sitting in an easily edited text box on your browser page.

Figure 8-4 shows the prompt that
you'll receive when you execute
ex8-4b.sql from i SQL*Plus
(by issuing the command
@http://gennick.com/sqlplus/ex8-4b). The prompt is
the result of the same ACCEPT command that you saw in Example 8-4. Each ACCEPT command, and each prompt that
SQL*Plus generates automatically in response to a
script's use of a substitution variable, results in
a separate HTML form to which you must respond by typing in a value
and clicking Continue.

Figure 8-5 shows a portion of the output after I
supplied "employee" as the table name and clicked
Continue. Even this relatively benign script has a problem with a
command not supported by i SQL*Plus. You can see
the error message resulting from my use of SET NEWPAGE 1.
Fortunately, the script continues to execute despite the one, invalid
command, and you can see the description of the
employee table, formatted into an HTML table,
following the error message.

The command reference in Appendix A indicates which commands are not allowed in i SQL*Plus.

i SQL*Plus is a wonderful thing, but its
browser-based interface seems better suited to running interactive
commands. If you need to run scripts, and especially when you wish to
schedule those scripts using cron or some other
scheduling software, stick to command-line SQL*Plus.