Thursday, 4 October 2012

Lesson -4 SQL*Plus commands



You can use SQL*Plus commands to manipulate SQL commands and PL/SQL blocks, and to format and print query results.

You can continue a long SQL*Plus command by typing a hyphen (-) at the end of the line and pressing [RETURN]. If you wish, you can type a space before typing the hyphen. SQL*Plus displays a right angle-bracket ($>$) as a prompt for each additional line.

You do not need to end a SQL*Plus command with a semicolon. When you finish entering the command, you can just press [RETURN].

You can use a number of SQL*Plus commands to edit the SQL command or PL/SQL block currently stored in the buffer. Or, you can use a host operating system editor to edit the buffer contents. SQL*Plus commands are not stored in the buffer; you must edit them at the prompt or re-enter the command.  Here is few commands,

SQL*Plus Commands
COMMAND
ABBREVIATION
PURPOSE
APPEND
A text
add text at the end of a line
CHANGE /old/new
C /old/new
change old to new in the line
CHANGE /text
C text
delete text from a line
CLEAR BUFFER
CL BUFF
delete all lines
DEL
(none)
delete a line
INPUT
I
add one or more lines
INPUT text
I text
add a line consisting of text
LIST
L
list all lines in the SQL buffer
LIST n
L n OR n
list one line
LIST *
L *
list the current line
LIST LAST
L LAST
list the last line
LIST m n
L m n
list a range of lines (m to n)

 

Once you have modified the buffer you can use the ``RUN'' command to execute the buffer contents. To save the contents of the buffer to a text file, use the ``SAVE file\_name'' command.

You can use your host operating system's default text editor to create and edit host system files and to modify the SQL*Plus buffer. To invoke the default text editor without leaving SQL*Plus enter:

          SQL> EDIT

EDIT  loads the contents of the buffer into your system's default text editor. When you exit from your text editor, the text is saved back into the current buffer.

To load the buffer contents into a text editor other than the default (EDITOR environment variable), use the SQL*Plus DEFINE command to define a variable, \_EDITOR, to hold the name of the editor.

          SQL> DEFINE_EDITOR = notepad

You can create a command file with a host operating system text editor by entering EDIT followed by the name of the file:

          SQL> EDIT file_name

EDIT adds the file name extension ``.SQL'' to the name unless you type a period and a different extension at the end of the file name.

You can retrieve a command file using the SQL*Plus:

          SQL> GET file_name

The START command retrieves a command file and runs the command(s) it contains. Use START to run a command file containing SQL commands, PL/SQL blocks, and/or SQL*Plus commands.

          SQL> START file_name

You can also use the @(``at'' sign) command to run a command file. The @ command lists and runs the commands in the specified command file in the same manner as the START command.

          SQL> @file_name

No comments:

Post a Comment