removing null valued columns from dataset in asp .net

I have a table which stores data with null valued columns for some entries .I want to retrieve only Not null data to the detail view. I tried the following

foreach(string strTableField in (objDataSet.Tables[0].Columns[i])) 
{
    if(objDataSet.Tables[0].Columns[i].Equals(null))
    {
        objDataSet.Tables[0].Columns.R开发者_开发技巧emove(strTableField);
       objDataSet.Tables[0].AcceptChanges();
    }

    i++;
}

but it is giving error .. Pls help me reg this ...

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You can use Select method of DataSet class. Like this:

DataRow[] rows = table.Select("field is not null");