Oracle SQL*Plus: The Definitive Guide, 2nd Edition

Commenting Your Scripts

If you write extensive scripts, you should write extensive comments. In fact, any time you write a script, no matter how short, consider including a few comments to explain the purpose of the script.

Comments may be placed in a script using any of the following three methods:

• By using the REMARK command

• By using double-hyphen characters

• By delimiting the comment by /* and */

Each method works a bit differently from the others. You will probably find yourself gravitating toward the /* . . . */ and -- delimiters. I find typing REMARK to be a bit cumbersome.

The REMARK Command

The REMARK command may be used to place comments in a SQL script. Any text on the same line following the REMARK command is considered a comment. The REMARK command may be abbreviated to REM as the following example shows:

REMARK This is a comment.
REM This is a comment too.

SQL*Plus doesn't look for substitution variables in the text following a REMARK command, so you are free to use ampersands and any other characters you like in your comments.

The /* and */ Delimiters

The /* and */ delimiters are familiar to many programmers and may be used to delimit comments in SQL*Plus. Comments created using this method may span multiple lines:

/*
This is the second line of a comment.
This is the third line.
*/

You can use /* and */ to add comments to SQL statements or to PL/SQL blocks. When you do this, such comments are not recognized by SQL*Plus, but rather by the database engine. Such comments may appear ...