How to remove value from GAE NDB Property (type BlobKeyProperty)

Question

It might be the most dumb question and my apologies for the same but I am confused

I have the following entity:

class Profile(ndb.Model):  
    name = ndb.StringProperty()  
    identifier = ndb.StringProperty()  
    pic = ndb.BlobKeyProperty() # stores the key to the profile picture blob

I want to delete the "pic" property value of the above entity so that it should look as fresh as if "pic" was never assigned any value. I do not intend to delete the complete entity. Is the below approach correct:

qry = Profile.query(Profile.identifier==identifier) 
result_record_list = qry.fetch()  
if result_record_list:  
    result_record_list[0].pic.delete()  # or result_record_list[0].pic = none # or undefined or null

I am deleting the actual blob referred by this blob key separately

score 3 · Accepted Answer · answered Feb 24 '14 at 14:24

3

assign None to it and put it back to the datastore.

result_record_list[0].pic = None
result_record_list[0].put()

answered Feb 24 '14 at 14:24

Omair Shamshir

2,126
13
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Thanks omair_77 for your reply – gsinha Feb 24 '14 at 14:55

score 1 · Answer 2 · edited May 23 '17 at 12:14

1

The datastore is an OO schemaless databse. So you can add and remove properties from the the Kind (ndb.Model) without the need of a schema update.

If you also want to cleanup the entities look at this anwser from Guido

edited May 23 '17 at 12:14

Community

1
1

answered Feb 24 '14 at 14:32

voscausa

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Thanks voscausa for your reply – gsinha Feb 24 '14 at 14:54

How to remove value from GAE NDB Property (type BlobKeyProperty)

2 Answers2