SQL Data Manipulation Statements - Database Systems - page 240

Example 46: Find all male students from Lenheim Hall who are not mathematics
majors:
12.12 Queries with Runtime Variables
It has already been established that runtime variables may be specified in an SQL data
manipulation statement. This applies to data insertion, update, and deletion statements;
it also applies to data retrieval statements (i.e. queries). The rules are unchanged.
Example 47: Produce a list of courses offered, starting from a particular course
which the user will specify:
Note: The ampersand (&) preceding the variable InputCode indicates that user will
be prompted to specify a value for the variable. This value will then be used to complete
the query. A double ampersand indicates (to Oracle) that the input is to be obtained from
the previous input value.
Example 48: Search for a course based on name or description, which the user will
specify:
The Oracle PL/SQL Accept statement may also be used but it must be specified
within a program block. The format is