Synopsis

                &n

Replaces each occurrence of &n with the corresponding parameter from the command line. For example, &1 would be replaced with the value of the first parameter specified on the command line.

                &var

Creates a SQL*Plus variable var and prompts for a value each time &var is encountered.

                &&var

Creates a SQL*Plus variable var and prompts for a value the first time &&var is encountered. Retains this value and uses it each time &&var is encountered subsequently until var is undefined.