How do I code an user prompt in a mainframe DB2 query?

Thanks,
Don

DB2 itself does not support that. But if you are using QMF, then put an ampersand in front of the variable.

select * from emp where empno = &empno_input

If you are using something besides QMF, you are out of luck (unless the query interface itself has a facility like QMF for variable prompting). SPUFI has no such facility unless they added it very recently.