Re: [Beankeeper-discussion] unique "keys "

[Shay M. <mat...@gm...>]

Thanks!

Brautigam Róbert wrote:
> Shay Matasaro írta:
>   
>> Hi ,
>>     
>
> Hi,
>
>   
>> my sample app has a company data object and a user data object, i would 
>> like usernames to be unique, across the board.
>>
>> i assume that maintaining this uniqueness per company is done via the 
>> collection container of the company ( Set<user> company users)
>>
>> how do i make sure that usernames are unique across companies(the 
>> parallel of unique property on a DB column), do i have to run a GetName 
>> query before each user addition?
>>     
>
> In short, yes. The longer answer is, that BeanKeeper is Java-side only,
> so you can't get part of your logic implemented in the database, like
> unique names, field constraints, hard relations, etc. You must do
> everything at the Java side.
> Of course BeanKeeper will use optimizations on the database, but the
> general direction is, that you should not need to, and if fact should
> not be able to do database (low) level stuff.
>
> Be aware also, that a persistent Set in BeanKeeper is unique always on
> persistence id (so persistent instance of object), and not using the
> equals() and hashCode() you implement. So Sets (and Lists also) store
> relations, instead of objects in this sense.
>
>   
>> thanks,
>> Shay
>>     
>
> Robert.
>
>