Hi,

I did a search on the forum before asking this silly question. Where and how should I check for null or empty values when using a data bound list.

At the moment I can add as many entries as I like even though some fields should not be able to be null (or empty). I am using the dev express grid, although this should apply to any data bound grid control.

Regards Craig.

Not nullable fields can't be set to null in 1.0.2004.2, this is build in.

In a grid, it's hard to set a field to null, as you can't specify such a value. What's therefore the situation you're referring to? A user which deletes the cell's contents by selecting it, and pressing DEL ?

Hi Otis,

Your code interprets null values to a particlar null representation, for example A null gui is System.Guid.Empty. My database field does not allow null values (the entity should not be able to commit to the database with empty values)

When I add new entities to the collection it does not enforce the not null values at any point until the entity collection is submitted for update.

I need to know how to ascertain whether an entity field is allowed to be null (on the client side) (System.Guid.Empty / string.Empty etc), and where I can enforce this in the entity collection. Perhaps in the validator?

I do not want the add to commit without the required fields entered.

Regards Craig

craigmain wrote:

Hi Otis,

Your code interprets null values to a particlar null representation, for example A null gui is System.Guid.Empty. My database field does not allow null values (the entity should not be able to commit to the database with empty values)

When I add new entities to the collection it does not enforce the not null values at any point until the entity collection is submitted for update.

I need to know how to ascertain whether an entity field is allowed to be null (on the client side) (System.Guid.Empty / string.Empty etc), and where I can enforce this in the entity collection. Perhaps in the validator?

In 1.0.2004.2 I've added this to adapter and selfservicing (in previous versions, it was only available in selfservicing): entity.Fields[index].IsNullable

Then, in an IEntityValidator implementation you check whether entity.Fields[index].IsNullable is false AND entity.Fields[index].IsChanged is true. If not, a not-nullable field hasn't received a value and you should throw an ORMEntityValidationException, which will terminate a transaction in progress.

This is enforced on save. I think that's the right place to do so, otherwise the user hasn't had time to add values

Set the IEntityValidator implementation in an entity initialisation include template or in a user code region. See the documentation for tips how to do that (1.0.2004.2) -> Using the generated code - Adding your own code to the generated classes