ibatis-user-java mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Clinton Begin <clinton.be...@gmail.com>
Subject Re: Select one set null instead of throwing exception
Date Mon, 05 Oct 2009 14:08:50 GMT
We've removed that exception anyway.  :-)

Popular community vote.

On Mon, Oct 5, 2009 at 12:07 AM, Guy Rouillier <guyr-ml1@burntmail.com>wrote:

> Ignore this.  I realized after taking a break that it doesn't work with
> primitive types.  I think the thing I find most frustrating with Java is
> that it doesn't treat primitive types in a consistent manner with classes
> derived from Object.
> Guy Rouillier wrote:
>> Currently, performing a single row select throws an exception if zero or
>>  > 1 rows are returned.  While this is certainly workable, an alternative
>> that would be easier on the programmer would be to set the result to null if
>> no rows are found, and only throw an exception if > 1 rows are found.
>> The documentation suggests doing a count to determine what situation you
>> are in, then issuing the appropriate select once you know.  But that will
>> result in an extra trip to the DB.  In a common scenario where you are
>> querying a primary key, you know that you will get zero or one row back.  So
>> rather than having to put the single row select into a try-catch block, a
>> more natural paradigm would be to assign the result and then check the
>> result for null.
> --
> Guy Rouillier
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: user-java-unsubscribe@ibatis.apache.org
> For additional commands, e-mail: user-java-help@ibatis.apache.org

View raw message