How to create a menu in SQLPlus or PL/SQL

Question

I have several scripts that I would like to start from a menu presented to the SQLPlus user. Something like:

Please make a selection:
1: Do script a

Answer 1

You can execute scripts from a master script:

CASE LOWER(&v_script_selection)
  WHEN 'a' THEN
    @script_a.sql
  WHEN 'b' THEN
    @script_b.sql
  WHEN 'c' THEN
    @script_c.sql
  ELSE
    DBMS_OUTPUT('No such option available')
END

&variablename is used to refer to the variable variablename in SQLPlus, much the same way $variablename is used in shell scripts. If variablename is undefined, then SQLPlus prompts the user for a value.

You can provide a path relative to the master script - the example relies on the supporting scripts to be in the same directory.