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From Andrew Melo <andrew.m...@gmail.com>
Subject Re: Validate uniqueness field
Date Tue, 30 Mar 2010 14:34:09 GMT
On Tue, Mar 30, 2010 at 9:13 AM, faust 1111 <faust451@gmail.com> wrote:
> It's very frightful for me implement uniqueness in this way
> create doc for each uniq field and keep it in actual state when i update docs.
>
> may be better check uniqueness only in application layer?
> now i don't think about distribute.

If you don't do it the way Jan suggested, you may end up with a race
condition, even if you don't distribute the database (i.e. if two
people register (nearly) simultaneously with the same username/email).
You would then have to support backing out/correcting any errors
manually in your application level code. If you're comfortable with
that, feel free, but Jan's way is much cleaner, in the long run.

best,
Andrew

> 2010/3/28 Jan Lehnardt <jan@apache.org>:
>> You need to have two documents with a unique ID each.
>>
>> Cheers
>> Jan
>> --
>>
>> On 27 Mar 2010, at 17:12, faust 1111 wrote:
>>
>>> but what if i have two unique fields
>>>  login
>>>  email
>>>
>>> 2010/3/28 J Chris Anderson <jchris@gmail.com>:
>>>>
>>>> On Mar 27, 2010, at 4:56 PM, faust 1111 wrote:
>>>>
>>>>> Hi
>>>>>
>>>>> In what way i cat implement validation of uniqueness?
>>>>> User
>>>>>  email: unique
>>>>>  login:  unique
>>>>>
>>>>
>>>> You can only have 1 unique field per database. you implement it by using
it as a docid, like
>>>>
>>>> {
>>>> "_id" : "user:unique",
>>>>   ...
>>>> }
>>>>
>>>> Chris
>>
>>
>



-- 
--
Andrew Melo

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