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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