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

Appendix B. SQL*Plus Format Elements

Several SQL*Plus commands control data formats using what is called a
format specification. A format
specification is a string of characters that tells
SQL*Plus exactly how to format a number, date, or text string when it
is displayed. The most notable of these commands is the COLUMN
command, which is used to format columns of output from a SELECT
query. Other commands exist as well. The complete list of SQL*Plus
commands that accept format specification strings is shown
here:
ACCEPT
Prompts the user to enter
a value from the keyboard.

COLUMN
Controls various aspects
of the way a column of data is displayed.

SET NUMBER
Defines the
default display format for numbers.

TTITTE, BTITLE,
REPHEADER,
REPFOOTER
Allow number format specifications to control the way numbers are
formatted in page headers, page footers, report headers, and report
footers.

There are three different broad types of values SQL*Plus can format:
numbers, character strings, and dates. Not all commands can handle
each type. With most commands, you can specify only number and date
formats. The COLUMN command is a good example. The ACCEPT command is
the only one that allows you to specify a date format string.

Format specification strings are made up of special characters that
have meaning to SQL*Plus in the context of formatting a value for
display. Numeric format strings, for example, tend to have many 0s,
9s, decimal points, and dollar signs. Date format strings tend to
include things like MM, DD, YYYY, etc. Character string formats are
the simplest of all because you have only one thing you can
influence: length.