Duplicate key and put_many

[aklaver]

Using Python SDK, deta==1.1.0:

from deta import Deta
deta = Deta("<some_key>")
db_put = deta.Base("put_db")
put_data = [{"key": '1', "fld_1": "dog"}, {"key": '2', "fld_1": "cat"}, {"key": '1', "fld_1": "fish"}]
db_put.put_many(put_data)
HTTPError: HTTP Error 400: Bad Request

put_data = [{"key": '1', "fld_1": "dog"}, {"key": '2', "fld_1": "cat"}, {"key": '3', "fld_1": "fish"}]
db_put.put_many(put_data)
{'processed': {'items': [{'fld_1': 'dog', 'key': '1'},
   {'fld_1': 'cat', 'key': '2'},
   {'fld_1': 'fish', 'key': '3'}]}}

From here Put:

If an item already exists under a given key, put will replace this item.

I assumed a duplicate key in put_many would not be an issue. Obviously I was wrong. Is this expected behavior or a bug?

[lemonyte]

I believe the HTTP API only supports duplicate keys in separate requests. If you put two items with the same key in one request, how does the API know which one to keep and which one to overwrite?

[aklaver]

The same way separate put's does by order of entry. 1) deta has no way of knowing in either case whether the order is correct. That is on the user. 2) If the item already exists the first entry would be an overwrite also. 3) put as described is a way to an UPSERT. If you want a duplicate error you use insert.

[aavshr]

hi @aklaver this is intended behavior as a put_many is taken as a single write, not as a set ordered writes. The order of the items in the array is not explicit enough to be taken as intentional for the API.

[aklaver]

That does not make sense. The API has no way of knowing whether individual put's are in the intended order either. The same process the creates the data for input can do that out of order before either iterating over the data with put or batching the data with put_many. The POLA would seem to me that doing a put would behave the same in each case. And as I mentioned earlier if double entry is something to be avoided then there is insert. If this is not going to be changed then the documentation needs to be updated to flag the behavior change.