How to check for the same row counts and same names in the datatables in C#

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C#

I have four datatables

datatable1 

                       DataView view = dt1.DefaultView;
                        view.Sort = "Wfname ASC";
                        DT1NEW= view.ToTable();
datatable2
			DataView view = dt2.DefaultView;
                        view.Sort = "Bfname ASC";
                        DT2NEW = view.ToTable();

datatable3
  			DataView view = dt3.DefaultView;
                        view.Sort = "Tfname ASC";
                        DT3NEW = view.ToTable();    

datatable4 

  			DataView view = dt4.DefaultView;
                        view.Sort = "Dname ASC";
                        DT4NEW = view.ToTable();

now based on the drop down selection i need to check whether all the datatables have same no of rows or same data or not without checking the extensions

if(ddlstype.SelectedValue == "1")
{
i need to check DT1NEW,DT2NEW and DT3NEW have same no of rows and  same names or not
}
if(ddlstype.SelectedValue == "2")
{
i need to check DT1NEW and DT2NEW  have same no of rows and  same names or not
}
if(ddlstype.SelectedValue == "3")
{
i need to check DT1NEW,DT3NEW and DT4NEW have same no of rows and  same names or not
}

that means if my DT1NEW has
Wfname
501.wav
502.wav
503.wav
and DT2NEW has
Bfname
501.doc
600.doc
604.doc
610.docx
and my DT3NEW has
501.docx
700.doc

it should show an error message that please upload equal number of files

in the next case if my dts are in this way
Wfname
501.wav
502.wav

and DT2NEW has
Bfname
501.doc
600.doc
and my DT3NEW has
501.doc
700.doc

then 501 record should be inserted into database and for the second row it should show that
502 does not match with 600 and 700
how can i do this

What I have tried:

i am new to this so can anyone help me out