Extract only certain columns from table and save it in text

Question

I am able to retrieve all the columns of values from a table using LINQ and display it. However, I only want to retrieve only certain columns (say column2 and column3) for display. How do I achieve that?

Also, I want to save those 2 columns of data in a text file, with no space and no separator between column2 and column3. How do I do it?

My code is as attached.

I would appreciate it very much for sample code.

thanks.