Jeremy Johnson said the following, On 2007-05-09 02:52: > Does anybody know of a tutorial or example of using linked lists in kexi with > postgresql? > > I'm trying to design a database which would be made easier if > some fields could be linked lists. A trivial example would be a field for > telephones which would be a null-terminated list of phones, e.g.: > Work->Home->Cell#1->Cell#2->Pager->Email->Voicemail->NULL > > So I'd like a TABLE called Phone_List: > PK id child_id Phone TYPE > 1 1 2 787-1234 (Work) > 2 2 3 787-4321 (Home) > 3 3 NULL 787-1111 (Cell) > 4 4 5 787-2222 (OvalOffice) > 5 5 6 787-4444 (Cell) > 6 6 NULL 787-5555 (Pager) > > And I'd also have a table for Person: > PK id Lastname Firstname Telephones > 1 1 Doe John 1 > 2 2 Bush George 4 > > > Of course I don't want to have to edit these Phone_List and Person tables > by hand. I need to create a form in Kexi which would allow me to to just > type in the telephone numbers on a CONTACTS form, > and kexi/python/ruby/postgresql would take > care of making sure that every telephone number had a correct child_id or > NULL. And I also need a method to remove a phone number (or if I delete a > person I need to delete all the telephone numbers for that person).
Why do you need parent-child relation for phone numbers? Maybe you just need an ordering? In any case Kexi does not "know" about such special cases (yet). This may be supported after 2.0 on users demand. Unless a special extension (taing care about updating hierarchical data) is developed at the GUI level in Kexi, users are forced to work only within the tabular view. That said, recursive queries are indeed useful, e.g. for implementing folder-like structures or other hierarchies without additional programming. For instance, Oracle offers a "CONNECT BY" (nonstandard, surprise?), while SQL99 defines the feature using "WITH" clause. I do not know whether current PostgreSQL release features this function, but there were attempts to extend it this way [1]. [1] http://gppl.moonbone.ru/ -- regards / pozdrawiam, Jaroslaw Staniek Sponsored by OpenOffice Polska (http://www.openoffice.com.pl/en) to work on Kexi & KOffice: http://www.kexi.pl/en, http://www.koffice.org KDE3 & KDE4 Libraries for MS Windows: http://kdelibs.com, http://www.kde.org _______________________________________________ Kexi mailing list [email protected] https://mail.kde.org/mailman/listinfo/kexi
