PL/SQL Programming problem

I am trying to write a PL/SQL program that does the following:

1. accepts user input
2. does validity checks on the user input
3. depending on a particular field the user enters, I want to run a specific query: For example: if the user enters a record type 'C' then run select query1 else run select query2
4. output the selected records to a user specified file

   Does anyone out there know how I can do this? I can't seem to get any help from the Oracle SQL*Plus documentation.

   I am running SQL*Plus on a Win 95 PC, that connects to an Oracle database stored on a Windows NT server. My version of Oracle is Oracle7 version 7.1.3.3.3

   If anyone is really familiar with this version of Oracle, and you do programming in C/C++ (not OWL), could you tell me how to use C/C++ to also solve the above problem (ie. I need to know the headers, and libraries that I should use in my C/C++ program).

   Any help would be greatly appreciated.

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