Regenerate the dataset and expressions

[Woody Splawn]

I am struggling with the basics in Ado.net using VB.net for non web
applications.

I have been using expressions in the design mode of strongly typed datasets
(.xsd files). However, I have discovered that if you regenerate the
dataset, the expression goes away. This is not what I want. I am wondering
how others deal with this issue. I can think of a couple of ways of dealing
with it. Don't know which is best.

One, don't regenerate the dataset. If you add a field in the underlying SQL
Server table, for example, and you want your dataset to reflect it, add it
explicitely in design mode of the .xsd file.

Two, If you are going to use expressions do them in code as opposed to in
the .xsd file. If this is bes, it becomes a matter of where to add them;
that is, in what event?

Any suggestions or thoughts would be appreciated.

Thank you.

 

[Ken Allen]

Hmmm. I attempted to define a new column based on an expression
(Parent.FieldName) in my strongly typed dataset and the field value is
always NULL. How did you get these columns to work at all?

-ken

 

[Woody Splawn]

You know that's a good question. When I asked the original question it had
been a while since I had worked with expressions and I think I did not have
all the facts. I will start a new thread called Expression aggregate
question.

Perhaps we can both find out.