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

3.3 Running SQL Queries

Executing a SQL query or statement is as simple as typing it into the
text box in the i SQL*Plus Workspace and pressing
the Execute button. When executing a single SQL statement, you do not
need to worry about terminating your statement with any special
character such as the semicolon. For example, you can execute:

SELECT * FROM dual;

or you can execute:

SELECT * FROM dual Any output from SQL statements that you execute will be displayed
below the Execute button.

3.3.1 Paging Through Results

When a SQL statement brings back a large number of rows,
i SQL*Plus displays results a page at a time. The
number of rows displayed per "page"
is determined by the PAGESIZE setting and defaults to 24.

i SQL*Plus places a page break in between
successive queries. Figure 3-8 shows two queries
executed with one click of the Execute button. You can see that
i SQL*Plus has displayed the result of the first
query and has followed that result with a Next Page button. Click
that button to see the next page with the result from the second
query.

One thing worth noticing about Figure 3-8 is that
the first of the two statements was terminated with a semicolon. When
executing multiple SQL statements in one go, you must terminate all
but the final one.

Use SET PAGESIZE n to specify a page size other than the default of 24 rows. Use SET PAGESIZE 0 to turn off pagination entirely, causing all rows returned by a query to be displayed in one potentially very long page.

3.3.2 Getting Output as Plain Text

By default, i SQL*Plus displays query results in
the form of an HTML table, as shown in Figure 3-9.
While visually pleasing, such a table may get in the way when you
want to copy and paste query results into a text document. If
you'd rather see query output as preformatted HTML,
issue the following command:

SET MARKUP HTML PREFORMAT ON

Output from queries executed after issuing this SET MARKUP command
will be formatted using the HTML <pre> and
</pre> tags, as shown in Figure 3-10. Use the command SET MARKUP HTML
PREFORMAT OFF to go back to using HTML tables.

For those who are strongly GUI-oriented,
i SQL*Plus provides a Script Formatting
preferences page from which you can toggle the PREFORMAT setting
using a radio button. Click on the Preferences button next to the
Logout button, look on the left side of the resulting page under the
heading System Configuration, click on Script Formatting, and scroll
way down to the Preformatted Output radio buttons. Choose whichever
option you prefer, scroll to the bottom of the page, and click the
Apply button. Click the Workspace tab to return to the workspace
page.

Any change you make to the PREFORMAT option is good only for the duration of your i SQL*Plus session. Chapter 14 talks more about customizing your SQL*Plus environment and shows some ways to make such customizations permanent or, in the case of i SQL*Plus, at least easy to repeat.