Re: Overlaying a DS Array In a LIKEREC DS

Eftimios Pantzopoulos wrote:

I found a tip from Bob Cozzi which detailed how to automatically map a DB record to a DS by using a prefix in the file declaration that was formatted to the qualified DS. This works and can be proven that only one move is required for the read by stepping through in DEBUG when *NODEBUGIO is NOT used.

The code looks like:

fafile uf e disk prefix('C.') usropn
:
d c ds likerec(rafile)
:
Read afile c;

The PREFIX keyword is unnecessary for what you want.

PREFIX is only necessary for the cases where you do not code the result DS on the I/O opcode.

The only thing the PREFIX keyword does is to cause the compiler-generated I specs to list fields C.NAME, C.ADDR instead of NAME and ADDR. Then during an input operation that doesn't have a result DS, the I specs would be run in the usual way, moving the fields from the input buffer into the RPG I spec fields, C.NAME and C.ADDR, one by one. For an input operation with a result DS, the I specs are skipped completely, as you've seen with your OPTION(*NODEBUGIO) test.