Subset of datatable

[bartee]

using vs 2005.

I created a dataset in the designer that fills a datatable I'm using to bind to several form controls.

I would like to create a subset of the result set and use this subset as the datasource for a drop down list.

For example, if the original datatable has a column called "company", I would like to create a list of the distinct company rows returned by the datatable.

What's the best way to do this? Can it easily be set-up in the designer?

Thanks in advance.

 

[ca8msm]

The DataTable has a Select method that you can use to filter the table using an expression.


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[bartee]

Thanks for the response but I'm not seeing this option.

I have a data adapter that fills the original datatable in my dataset. All done in the designer.

I want to keep this original configuration but, in addition, I want to build another data table off the results of the original. I'm not looking to hit the database with another query -- just want to get the distinct values from a column of the original data table and bind them to a drop down.

Sorry if I'm misunderstanding your original reponse.

Thanks again.

 

[jbenson001]

What do you mean you don't see that option?
Ex:

Dim foundrows() As DataRow
foundrows = YourDS.Tables("YourTable").Select("Filter")
ddl.DataSource = foundrows

It does not hit the DB again, it selects the rows, according to the filter your supply, from the existing datatable.

Jim

 

[bartee]

I wasn't seeing the option in the designer.

I put the code sample in the page load and when I replace "YourDS" with the name of the dataset I've created in the designer, I get the following:

"reference to a non-shared member requires an object reference"

Sorry if I'm missing the obvious but am fairly new to .net.

Thanks very much again.

 

[jbenson001]

You cannot do it in the designer, it needs to be done in code. My code example above should go after you fill your dataset initially in the page load:

if not ispostback then
   dataadapter.fill(yourds)
   whatever.databind

   .. code from above here ...
end if