preventing duplicate records: how to?
preventing duplicate records: how to?
- Subject: preventing duplicate records: how to?
- From: Tom Woteki <email@hidden>
- Date: Tue, 27 May 2003 12:01:04 -0400
I am seeking an alternative to an approach I have for preventing the
insertion or update of records that duplicate selected fields of
already existing records. My approach is based on comparing
EOGlobalIDs. I keep thinking I have missed something obvious or that
there may be preferred way of doing this.
Here is an example of my situation: Say I have an entity, Person, whose
primary key does not involve any of N other attributes, 2 of which are
firstName and surname. I want to prevent the insertion of new Persons
or updating of existing Persons that would result in duplicates of
these 2 attributes. (Note: These are not the only 2 attributes for
which I want to avoid duplicates, so simply making their combination
the primary key would not solve my problem.)
Here is the approach I use: Say p is a new Person entity I am about to
insert (i.e. saveChanges() after insertObject() has been called on some
editingContext). I fetch any entities whose 2 attributes from above
match those of p. If I find any whose EOGlobalID in the editing context
is different than p's I conclude I am about to create a duplicate and
prevent the save. I use a similar technique for updates.
Is there another way, a preferred way, of doing this?
Thanks
Tom
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