RE: v13+ self referentail relations
Thanks On Fri, 11 Jan 2019 17:19:57 +, Timothy Penner wrote: >> this used to be possible. > > In 2004 and prior, yes... But it is no longer possible starting with v11. > >> what happens when an older structure with a self referential >> relation is upgraded? > > It looks like the relationship is removed once you upgrade to v11. > > -Tim > > > > Timothy Penner > Senior Technical Services Engineer > > 4D Inc > 95 S. Market Street, Suite #240 > San Jose,CA 95113 > United States > > Telephone: +1-408-557-4600 > Fax: +1-408-271-5080 > Email: tpen...@4d.com > Web: www.4D.com > --- Gas is for washing parts Alcohol is for drinkin' Nitromethane is for racing ** 4D Internet Users Group (4D iNUG) Archive: http://lists.4d.com/archives.html Options: https://lists.4d.com/mailman/options/4d_tech Unsub: mailto:4d_tech-unsubscr...@lists.4d.com **
RE: v13+ self referentail relations
> this used to be possible. In 2004 and prior, yes... But it is no longer possible starting with v11. > what happens when an older structure with a self referential relation is > upgraded? It looks like the relationship is removed once you upgrade to v11. -Tim ** 4D Internet Users Group (4D iNUG) Archive: http://lists.4d.com/archives.html Options: https://lists.4d.com/mailman/options/4d_tech Unsub: mailto:4d_tech-unsubscr...@lists.4d.com **
RE: v13+ self referentail relations
this used to be possible. what happens when an older structure with a self referential relation is upgraded? >> how do I draw a self-referential relation? > You cannot make a single field both the primary and foreign keys of a > relation. You must choose two different fields. > For example, you can make [Table_1]Field1 related to [Table_1]field2 > Reminder: the fields must be compatible with each other as you would > not be able to relate a longint field to an alpha field... Hell is other people Jean-Paul Sartre ** 4D Internet Users Group (4D iNUG) Archive: http://lists.4d.com/archives.html Options: https://lists.4d.com/mailman/options/4d_tech Unsub: mailto:4d_tech-unsubscr...@lists.4d.com **
RE: v13+ self referentail relations
> how do I draw a self-referential relation? You cannot make a single field both the primary and foreign keys of a relation. You must choose two different fields. For example, you can make [Table_1]Field1 related to [Table_1]field2 Reminder: the fields must be compatible with each other as you would not be able to relate a longint field to an alpha field... > how do I modify the system tables? You cannot directly modify the system tables. The system tables represent the underlying structure, so to change the system tables you would change the structure and then the system table will automatically reflect that change. -Tim ** 4D Internet Users Group (4D iNUG) Archive: http://lists.4d.com/archives.html Options: https://lists.4d.com/mailman/options/4d_tech Unsub: mailto:4d_tech-unsubscr...@lists.4d.com **