Re: Newbie question
Re: Newbie question
- Subject: Re: Newbie question
- From: Pascal Robert <email@hidden>
- Date: Thu, 07 Apr 2011 06:39:34 -0400
Le 2011-04-06 à 23:48, Chuck Hill a écrit :
> That is going to leave you with a race condition. The only certain way to prevent the creation of duplicates is to put an unique constraint on the database. Then you have to catch the database exception (EOGeneralAdaptorException) in your code and handle appropriately. The ugly part is that the exception message returned is different for each database which makes doing this in a database agnostic way slightly challenging.
Example for H2:
try {
editingContext().saveChanges();
} catch (EOGeneralAdaptorException ex) {
EOAdaptorOperation operation = (EOAdaptorOperation)((NSMutableArray)ex.userInfo().valueForKey("EOAdaptorOperationsKey")).objectAtIndex(0);
if (operation.exception().getMessage().contains("Unique index or primary key violation")) {
throw new SomeException();
}
> Chuck
>
> On Apr 6, 2011, at 8:21 PM, Paul D Yu wrote:
>
>> Based on the column/attribute in your DB/EOModel that would make your consider the record/EO to be duplicate of another, you should implement a method that would check for those values in the existing set.
>>
>> I don't think there is a one line solution to what you are seeking.
>>
>> Paul
>> On Apr 6, 2011, at 10:52 PM, Mr Tonnew wrote:
>>
>>> Hi,
>>>
>>> How do I avoid committing duplicate entries in the DB? I have a form
>>> from where I take entries. Is there a single line of code that can
>>> accomplish this?
>>>
>>> MR
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> --
> Chuck Hill Senior Consultant / VP Development
>
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