New ITypeHandler NullValue property

[Michael Schall <mi...@gmail.com>]

Is this the null value "coming from" the database, or "going to" the
database?
>From the code it looks like coming from since it is used in the
ResultProperty class.

For example if I have a nullable varchar field in the database and in an
instance of a class I would like this to be represented by an empty string.

My type handler vb code would look like this:

        Public ReadOnly Property NullValue() As Object Implements
IBatisNet.DataMapper.TypeHandlers.ITypeHandlerCallback.NullValue
            Get
                Return ""
            End Get
        End Property

If I want null database fields to remain null, the code would look like the
following

        Public ReadOnly Property NullValue() As Object Implements
IBatisNet.DataMapper.TypeHandlers.ITypeHandlerCallback.NullValue
            Get
                Return Nothing
            End Get
        End Property

Is this correct?  There are no docs that I can find about this new
property.  I know docs for this release are not completed yet. :)

Thanks for your time.

Mike

Re: New ITypeHandler NullValue property

[Gilles Bayon <ib...@gmail.com>]

On 1/26/07, Michael Schall <mi...@gmail.com> wrote:
>
> I could do it on a resultMap/parameterMap basis, but a legacy database I'm
> using stores empty string rather than null for all string.  The typeHandler
> seems like an easier solution as I can put it in the config file once and
> forget about it...  Is there anything wrong doing it this way?


No, that's will do the job.
One remark, your typehandler can override iBatisNet's configuration for
string type.
Search a converstion named "NUMBER dbType - Double/Decimal .NET Type  " in
the "user-cs" list.

I will try it returning Nothing/null.
>
> Thanks for the response.
> Mike --
> Cheers,
> Gilles
>
> <a href="http://www.amazon.com/gp/registry/6JCP7AORB0LE">Wish List</a>

Re: New ITypeHandler NullValue property

[Michael Schall <mi...@gmail.com>]

I could do it on a resultMap/parameterMap basis, but a legacy database I'm
using stores empty string rather than null for all string.  The typeHandler
seems like an easier solution as I can put it in the config file once and
forget about it...  Is there anything wrong doing it this way?

I will try it returning Nothing/null.

Thanks for the response.
Mike


On 1/25/07, Gilles Bayon <ib...@gmail.com> wrote:
>
> It's always represent a .NET value.
> For example if I have a DateTime property with DateTime.Min as value, I
> will set paremeterMap property attribute nullValue="01/01/0001 00:00:00" to
> save null in db
> On a resultMap property the same nullValue="01/01/0001 00:00:00", will
> transform a database value null to DateTime.Min.
>
> Hopes this help.
> Just needs to read the doc
> http://ibatis.apache.org/docs/dotnet/datamapper/ch03s04.html#id357123
>
> You don't need to use a TypeHandler
>
> --
> Cheers,
> Gilles
>
> <a href="http://www.amazon.com/gp/registry/6JCP7AORB0LE">Wish List</a>

Re: New ITypeHandler NullValue property

[Gilles Bayon <ib...@gmail.com>]

It's always represent a .NET value.
For example if I have a DateTime property with DateTime.Min as value, I will
set paremeterMap property attribute nullValue="01/01/0001 00:00:00" to save
null in db
On a resultMap property the same nullValue="01/01/0001 00:00:00", will
transform a database value null to DateTime.Min.

Hopes this help.
Just needs to read the doc
http://ibatis.apache.org/docs/dotnet/datamapper/ch03s04.html#id357123

You don't need to use a TypeHandler

-- 
Cheers,
Gilles

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