Subject Re: creating unique key : usingprimair key and foreign key From Alex Safian <noway@noway.com> Date Fri, 05 Feb 2021 18:08:52 -0500 Newsgroups dbase.getting-started Mervyn, are you saying not to use autoinc? I thought creating unique primary keys in a multiuser environment is exactly what autoinc was for. Otherwise, who needs it? What's it there for? Mervyn Bick Wrote: > In a multi-user system one can't guarantee that the last record in the > main table is the one you've just saved.  Another user may have saved a > record a fraction of a second after you.  SQL RDBMs make provision for > a programmer to get the value of the primary key of a record just saved. > dBASE doesn't. :-( > > The solution is not to use an autoinc field but rather use a separate > sequence generator.  Primary keys do not need to be in numerical order > in a table.  They just need to be unique.  If you want to list records > in the order in which they were saved add a timestamp.  Get a value > BEFORE saving the new parent record and use that.  There is code in the > dUFLP (seqval.cc) to do this. > > Mervyn. >