Roll your own. this solves the control issue. and you can extend the sequence number generator to other things - not just numeric values.
Think License plates alphas and numerics, embedded dates, fixed text, just about anything. > John, > Well I stand corrected. > > On Wed, Mar 8, 2017 at 8:03 AM, John DeSoi via 4D_Tech <[email protected] >> wrote: > >> >>> On Mar 8, 2017, at 9:09 AM, Kirk Brooks via 4D_Tech < >> [email protected]> wrote: >>> >>> Currently, let's say a user begins a transaction and the new record gets >>> the sequence number. Before that transaction is completed another user >>> starts a new record (or that user starts another process to create >> another >>> record) - and gets the same sequence number. The first one to save wins. >> >> This is not true if you are using 4D's Sequence number function. As long >> as you create a new record (or duplicate one) other processes will get a >> different sequence number. >> > > It is still a little wonky, though. I decided to test out what happens > with this test code: > > // start a process and call seq num > $n:=Sequence number([ORDERS]) > $msg:="At start: "+String($n) > > $id1:=New process("__testSeq";0) > $id2:=New process("__testSeq";0) > $id3:=New process("__testSeq";0) > > While (Process state($id1)>=0) | (Process state($id2)>=0) | (Process > state($id3)>=0) > > DELAY PROCESS(Current process;60) > > End while > > $n:=Sequence number([ORDERS]) > $msg:=$msg+"\rat end: "+String($n) > ALERT($msg) > > > The __testSeg method is: > > $n:=Sequence number([ORDERS]) > DELAY PROCESS(Current process;60*3) > ALERT("Proc # "+String(Current process)+"; seq n = "+String($n)) > > > Basically grab the seq num at the start (the test itself runs in a new > process, not the app process) then start three other processes which grab > the seqnum and delay for a few seconds before displaying an alert. > > Each new process incremented the sequence number as you said. Back in the > original process, once all the others are done grab the seq number again. > To my surprise this is always the same as the start which seemed odd > because the sequence number actually gets incremented by testing it, though > not for every test. > > Curious about it I inserted a delay between $id1 and $id2 - I wanted to > wait for the new process to have time to spawn and grab the sequence number > again. This 'mid' number was always the same as the starting number. So it > seems that each process gets only one call to the sequence number for a > given table until, presumably, the underlying table has a new record > created and saved. Just for fun I threw in a SAVE RECORD on the table (no > record was selected) to no effect. > > If a subsequent call to sequence number is made it causes the sequence to > increment. So the final call my test method makes causes the sequence to > increment by 3 even through at the time that call is made the other > processes have quit and 'released' their numbers. ------------ Hell is other people Jean-Paul Sartre ********************************************************************** 4D Internet Users Group (4D iNUG) FAQ: http://lists.4d.com/faqnug.html Archive: http://lists.4d.com/archives.html Options: http://lists.4d.com/mailman/options/4d_tech Unsub: mailto:[email protected] **********************************************************************
