Subject Re: Invoice number From Bami Onwu <bamionwu@yahoo.com> Date Mon, 07 Sep 2020 09:59:40 -0400 Newsgroups dbase.getting-started Thanks to everyone of you. Akshat please can you attach a brief example of this in a form?. I will quite appreciate. Thank you. Bami Akshat Kapoor Wrote: > On 06.09.2020 04:59, Bami Onwu wrote: > > Hi all, > > > > I created invoicing app for a customer and it's working fine on standalone. When working under multiuser, it assigns one invoice number to two users. > > > > The invoice numbering is no more unique. I need advice on how to go about this. > > Good Evening Bami, > We do not have any info as to when and how new invoice numbers are being > generated. So cannot say for sure but I agree with Ken that do not > generate invoice numbers before hand. Generate them at the last moment > before actual saving of row. > > I have been using this system for the past 15+ years and never had any > issue. > > Before that I also used to face this issue but ever since this system > has been implemented never faced this issue. > > Some info regarding this system. > When a user clicks on new invoice button I assign -1 as the invoice number. > (If you assign last number +1 here there will always be issues due to > the time gap involved in assigning and saving of first row with that value) > The text where invoice number is displayed uses iif > > form.header.cash_no.text = "Invoice No. <font color='red'><b>"+ > iif(form.minvoice = -1 , "new" , form.minvoice)        + "</b></font> " > > So the user does not feel awkward that how come a new number is -1 > > In the save pushbutton event I use the following line > form.minvoice = iif(form.minvoice>0 , form.minvoice ,form.last()+1 ) > > i.e. if form.invoice (my invoice number) is greater than 0 i.e valid > then no change otherwise fetch the last Invoice number from the table > and increment it by 1 before using it. > > function last() > local mcount > form.salesdatamodule1.last.requery() > mcount = form.salesdatamodule1.last.rowset.fields["numb"].value > if mcount = null > //mcount will be null when there are no rows in the table >         mcount = 0 > endif > return mcount > > > SQL for query last > Select max(invoice_no) as numb from sales WHERE mast <>0 > > The codes being used are according to my needs and are for example only. > Make changes according to your own need. > > There should not be any gaps in invoice numbering and there should not > be duplicates are the two key necessary requirements of an invoicing > system. To achieve this there should be bare minimum time gap between > generating new invoice number and saving the first row so that the next > person who generates new invoice number is assigned a new number. > > Regards > Akshat