Diff SFLNXTCHG and READC in a DoW loop

[mansi400]

Hi,

If ever I need to read the changed record of a subfile I do the following

Readc SFL01
Dow Not %EOF(SFL01)
Readc SFL01
<Some operations>
EndDo

It works fine and I am able to get all the changed records of the subfile. As per my understanding SFLNXTCHG will also give me the changed recrods of a subfile. So what is the diff between the two?

Thanks!

[jamief]

Re: Diff SFLNXTCHG and READC in a DoW loop

SFLNXTCHG is the keyword in DDS that allows the readc to work in RPG.
What is odd is it need not be present in the DDS to work.

jamie

[DAG0000]

Re: Diff SFLNXTCHG and READC in a DoW loop

SFLNXTCHG represents a flag on the subfile record that indicates whether or not the READC will read the record. This allows you control over whether or not you want to do a READC on a subfile record.

[MichaelCatalani]

Re: Diff SFLNXTCHG and READC in a DoW loop

Just to clarify a bit more:


The readc opcode will always read a physically changed subfile record. It does not need the SFLNXTCHG keyword to do this.

But there are times when you want to force the readc to read a subfile record, whether it was changed or not. Suppose you have a subfile screen of item numbers. After keying the item numbers, every subfile record would technically be picked up by the readc since they were changed. (Item numbers entered. ) Now, our code would validate each of the item numbers to make sure they were valid. If there is an invalid item number, we need to set the SFLNXTCHG flag so that the readc will pick that record back up in case the user doesnt change the item number. Without using the SFLNXTCHG, our program would perform validation on the item number entered, but if the user doesnt change the item number, that subfile record wouldnt be picked up on the next readc loop. This would make our program think that all item numbers were valid. By setting on the SFLNXTCHG keyword anytime we flag the item number as invalid, it will force the readc to read that subfile record until a valid item number is entered.

So thats all SFLNXTCHG really does. It sets a flag so that the readc will read that record, even if it wasnt actually physically changed by the user.

[sms_mitschs]

Re: Diff SFLNXTCHG and READC in a DoW loop

... by the way:

Readc SFL01
Dow Not %EOF(SFL01)
Readc SFL01
<Some operations>
EndDo

... will omit the first changed subfile record! The following would be better:

Readc SFL01
Dow Not %EOF(SFL01)
<Some operations>
Readc SFL01
EndDo

Just to keep the things correct ...

[mansi400]

Re: Diff SFLNXTCHG and READC in a DoW loop

Oops!!! My Bad... Actually.. that is wat i meant :-P