A few days ago I ran some data migration process that resulted in a few number pf oddities that I am trying to fix with. Here's my situation - I hope one of you out there could help.
Background: My app had a User model with two StringPropertyList properties representing a 1:many relationship between a user and an Item model. The properties, completed_items & in_progress_items, held the key_name of an Item model. Every time and Item model was created, I also added its key_name to the User who created it. Since these lists grew to contain several hundred of items, I decided to migrate their data into two new models: UserCompletedItem & UserInProgressItem. Each model holds the item key_name and the user key_name. As part of the migration, I ran on all User entities, fetched the user's completed_items & in_progress_items lists and for each item I created a new UserCompletedItem / UserInProgressItem. After creating all new entities, I set the completed_items & in_progress_items properties to empty lists (User.completed_items=[] & User.in_progress_items model=[]) to reduce the size of each User entity. In addition to that, I removed from the code any reference to User.completed_items or User.in_progress_items and all data access activities are performed using the two new models. The problem: When I look at the User entities using GAE's Admin's Data Viewer, the value of the two properties that I set to [] appear as <missing> (an indication that the process of setting an empty list actually worked). However, for a small number of entities, the two properties equal to <null>. In addition to that, in my code, whenever I try to fetch an entity with a <null> value, the following exception gets thrown and the fetch fails: *Error_type:<class 'google.appengine.api.datastore_errors.BadValueError'> ; Error_message: Property in_progress_item is required* My question, how can I fetch these entities with <null>? Is there a way to change the <null> values to []? Alternatively, can I remove the two properties from the Model class (since I am not going to reference them in the code anymore) and things will work normally? Thanks, -jay -- You received this message because you are subscribed to the Google Groups "Google App Engine" group. To view this discussion on the web visit https://groups.google.com/d/msg/google-appengine/-/lXXCbmSNvjIJ. 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.