Hi, I'm having a bit of trouble understanding how to use parents/children properties within transactions.
I have divided up my "Thumbnails" and the actual "Large Image" into two separate models to save processing power, but when I upload, I want to make sure that both entities are updated--therefore I have to use transactions. Short version (incase the answer is something simple): ========================================== Can I query to find out the children entities of a Parent entity? Long Version: =========== Key fact - thumbnails is connected to the Large Image (bin) via the column "bin_id" The code in Exhibit 1 doesn't work because I get the 'error "ImageThumb" must have a complete key before it can be used as a parent'. So I tried to: 1. .put() ImageThumb 2. assign it as a parent 3. .put() Bin (the large image) 4. get the ID from step 3 5. insert the id in the ImageThumb and .put() it again. I got the error: you can't put an entity more than once in appengine! So my last resort was to just get rid of binID and do steps 1-3. This works! But now i'm stuck as to getting the Large Image (child) for a specific thumbnail(parent). Code Exhibit 1 ====================== def uploadImages(self): thumb_db = ImageThumb() thumb = images.resize(image_data, 150,150,images.JPEG) thumb_db.thumb = db.Blob(thumb) bin_db = ImageBin(parent=thumb_db) bin_db.image = image_data bin_put=bin_db.put() bin_id = bin_put.id() thumb_db.binId = bin_id <<=== need binId so that thumbnail is linked to actual image (so I can use get by id class) thumb_db.type= "Picture" thumb_put = thumb_db.put() thumb_id = thumb_put.id() --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Google App Engine" group. To post to this group, send email to google-appengine@googlegroups.com To unsubscribe from this group, send email to google-appengine+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en -~----------~----~----~----~------~----~------~--~---