How is that useful? How can we access data from the database?
Answer
Pro*C is actually a pre-compiler for Oracle database access within C code.
You write your code with statements like:
int sal;
EXEC SQL SELECT salary INTO :sal FROM employees WHERE name = 'Diablo, Pax';
if (sal < 100000)
printf ("I'm not being paid enough!\n");
intermixing regular C with Pro*C statements (as you can see) and then you run it through the Pro*C compiler.
What comes out of that is a C program which has the Pro*C statements replaced with the equivalent function calls which will do the same thing.
You then run this through a real C compiler and it gives you the executables to be run to perform whatever tasks you want.