How to change the DataTable Column Name?

Question

Try this:

dataTable.Columns["Marks"].ColumnName = "SubjectMarks";

Rename the Column by doing the following:

dataTable.Columns["ColumnName"].ColumnName = "newColumnName";

 dtTempColumn.Columns["EXCELCOLUMNS"].ColumnName = "COLUMN_NAME";                        
 dtTempColumn.AcceptChanges();

Use:

dt.Columns["Name"].ColumnName = "xyz";
dt.AcceptChanges();

or

dt.Columns[0].ColumnName = "xyz";
dt.AcceptChanges();

after generating XML you can just Replace your XML <Marks>... content here </Marks> tags with <SubjectMarks>... content here </SubjectMarks>tag. and pass updated XML to your DB.

Edit: I here explain complete process here.

Your XML Generate Like as below.

<NewDataSet>
      <StudentMarks> 
          <StudentID>1</StudentID>
          <CourseID>100</CourseID>
          <SubjectCode>MT400</SubjectCode>
          <Marks>80</Marks>
      </StudentMarks>
      <StudentMarks> 
          <StudentID>1</StudentID>
          <CourseID>100</CourseID>
          <SubjectCode>MT400</SubjectCode>
          <Marks>79</Marks>
      </StudentMarks>
      <StudentMarks> 
          <StudentID>1</StudentID>
          <CourseID>100</CourseID>
          <SubjectCode>MT400</SubjectCode>
          <Marks>88</Marks>
      </StudentMarks>
  </NewDataSet>

Here you can assign XML to string variable like as

string strXML = DataSet.GetXML();

strXML = strXML.Replace ("<Marks>","<SubjectMarks>");
strXML = strXML.Replace ("<Marks/>","<SubjectMarks/>");

and now pass strXML To your DB. Hope it will help for you.