DataSet question - C# / C Sharp

Tommy Lang

I am creating a database application that uses the dataset.
The dataset holds three different tables.
I can access each table, no problem there. But how can I combine
data from the different tables into a new table.
Should/could I use views, relations ? It is possible to send an sql
query to my dataset?

I am hoping to avoid having to save the data in the dataset to my
database and then send a sql question down to the database and reload
everything.

Thanks
/Tommy

Nov 16 '05 #1

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1963

Nicholas Paldino [.NET/C# MVP]

Tommy,

It would be possible to create a new table where the column expressions
reference the columns in the other tables. I believe that if the values are
changed in the table, the calculated columns will have the correct value.

You can not feed a select statement to the DataTable. However, you can
call the Select method, passing in filters, which I believe can reference
related tables.

Hope this helps.
--
- Nicholas Paldino [.NET/C# MVP]
- mv*@spam.guard. caspershouse.co m

"Tommy Lang" <mu*****@yahoo. se> wrote in message
news:78******** *************** **@posting.goog le.com...

I am creating a database application that uses the dataset.
The dataset holds three different tables.
I can access each table, no problem there. But how can I combine
data from the different tables into a new table.
Should/could I use views, relations ? It is possible to send an sql
query to my dataset?

I am hoping to avoid having to save the data in the dataset to my
database and then send a sql question down to the database and reload
everything.

Thanks
/Tommy

Nov 16 '05 #2

Miha Markic [MVP C#]

Hi Nicholas and Tommy,

"Nicholas Paldino [.NET/C# MVP]" <mv*@spam.guard .caspershouse.c om> wrote in
message news:uv******** *****@TK2MSFTNG P12.phx.gbl...

Tommy,

It would be possible to create a new table where the column expressions reference the columns in the other tables. I believe that if the values are changed in the table, the calculated columns will have the correct value.

I would recomended expressions only for read-only data. If you have
editing - avoid them.
Create another table, copy the data from tables into it.
You might take a look at
HOW TO: Implement a DataSet JOIN helper class in Visual C# .NET
http://support.microsoft.com/default...Product=adonet

--
Miha Markic [MVP C#] - RightHand .NET consulting & development
miha at rthand com
www.rthand.com

Nov 16 '05 #3

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