Thanks guys! Think I'll just concatenate parent and child ID for display purposes and keep the rest as it is.
Fred On 1 Okt., 08:16, John Patterson <jdpatter...@gmail.com> wrote: > You can use DatastoreService.allocateIds() to get a range of unique > keys that you can then assign to the children. The kind name can be > any old String - not just an existing kind. This method does not > guarantee the ids will be sequential but they will be unique. > > If you really need sequential ids you can use memcache's atomic > increment method. If the value is not found in memcache you can do a > query to find the maximum sequence number in the datastore and use the > memcache increment method that allows you to specify an initial > missing value atomically. > > John > > On 30 Sep 2010, at 17:28, Fred wrote: > > > Hi Group, > > > I know key ids are only unique across entity groups so what GAE + JDO > > gives me is: > > /Parent[1]/Child[1] > > /Parent[1]/Child[2] > > /Parent[1]/Child[3] > > > /Parent[2]/Child[1] > > /Parent[2]/Child[2] > > > /Parent[3]/Child[1] > > > etc. > > > What I need to achieve (aka implement) is a way to assign keys in the > > following fashion: > > /Parent[1]/Child[1] > > /Parent[1]/Child[2] > > /Parent[1]/Child[3] > > > /Parent[2]/Child[4] > > /Parent[2]/Child[5] > > > /Parent[3]/Child[6] > > > etc... so child ids are in sequence across entity groups (or at least > > unique). Does anyone have experience with this or any thoughts on how > > to go about it in a secure fashion? > > I can't seem to come up with a secure way of doing this, but don't > > want to give up on it because it would give my use case a lot of > > querying power. > > > Hope someone can help. > > Thanks in advance, > > Fred > > > -- > > You received this message because you are subscribed to the Google > > Groups "Google App Engine for Java" group. > > To post to this group, send email to google-appengine-java@googlegroups.com > > . > > To unsubscribe from this group, send email to > > google-appengine-java+unsubscr...@googlegroups.com > > . > > For more options, visit this group > > athttp://groups.google.com/group/google-appengine-java?hl=en > > . -- You received this message because you are subscribed to the Google Groups "Google App Engine for Java" group. To post to this group, send email to google-appengine-j...@googlegroups.com. To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en.
