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Subject: Re: [WO-DEV] validateForSave() question
From: Aaron Rosenzweig <aaron@chatnbike.com>
In-Reply-To: <2e913111-33ed-4dbb-9273-bdc6acafa932@yahoo.com>
Date: Wed, 25 Feb 2026 21:37:54 -0500
Cc: WebObjects & WOnder Development <webobjects-dev@wocommunity.org>
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References: <list-35338440@post.selbstdenker.com>
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To: Theodore Petrosky <tedpet5@yahoo.com>

You could have a unique index on the compound key of the many-to-many =
table. That would prevent duplicates at the DB level.

You could give a user friendly message with either validateForSave()

> On Feb 25, 2026, at 7:57 PM, Theodore Petrosky <tedpet5@yahoo.com> =
wrote:
>=20
> yea, it is a many to many. I put both validateForInsert and ForSave =
with logs to see them fire. I think I need to check for duplicates in =
the validateForSave.
>=20
> so here is the quandary there is an entity Event. an event has a show =
and a show has an array of books. people are assigned to books. right =
now Jon is assigned to book 1 of event.show.LionKing.
>=20
> If I edit the books (EditRelationshipEmbeddedEventBook) I can assign =
Jon to two books. This is what I am trying to eliminate. The possibility =
of a human error (that means that Jon gets paid twice.)
>=20
> Whoops
>=20
> Ideas?
>=20
> Ted
>=20
>=20
> On 2/23/26 7:52 PM, Aaron Rosenzweig wrote:
>> If it=E2=80=99s strictly a toMany relationship, I don=E2=80=99t see =
how they could be added twice.
>>=20
>> Is it a many-to-many? In that case, the same person could be added =
twice. In that case, I=E2=80=99d put the validateForInsert() on the join =
table. I=E2=80=99d try to find at least one other join table pointing to =
the same person and entity.
>>=20
>>> On Feb 23, 2026, at 5:50 PM, Theodore Petrosky <tedpet5@yahoo.com> =
wrote:
>>>=20
>>> I am trying to add a check in validateForSave. my entity has a =
toMany relation with my Person entity. I need to  check if a person has =
been added twice.
>>>=20
>>> So basically, if Jon has been added twice throw the validation =
exception. so I guess, here is an array of persons, are they all unique?
>>>=20
>>> Am I being clear?
>>>=20
>>> public void validateForSave() throws =
NSValidation.ValidationException {
>>>=20
>>> Ted
>>>=20
>>> BTW, I tried to send this to webobjects-dev@lists.apple.com, but it =
looks like it has been down for a couple of days or longer.
>>>=20
>>>=20
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>>>=20