Datatable. Select distinct

Code
  ///   <Summary>
/// Returns the datatable after the select distinct operation.
///   </Summary>
///   <Param name = "sourcetable"> Source data table </Param>
///   <Param name = "fieldnames"> Field set </Param>
///   <Returns> </returns>
Private Datatable selectdistinct (datatable sourcetable, Params   String [] Fieldnames)
{
Object [] Lastvalues;
Datatable newtable;
Datarow [] orderedrows;

If (Fieldnames =   Null   | Fieldnames. Length =   0 )
Throw   New Argumentnullexception ( " Fieldnames " );

Lastvalues= New Object[Fieldnames. Length];
Newtable= NewDatatable ();

foreach ( string fieldname in fieldnames)
newtable. columns. add (fieldname, sourcetable. columns [fieldname]. datatype);

orderedrows = sourcetable. select ( "" , string . join ( " , " , fieldnames ));

foreach (datarow row in orderedrows)
{< br> If ( ! fieldvaluesareequal (lastvalues, row, fieldnames)
{< br> newtable. rows. add (createrowclone (row, newtable. newrow (), fieldnames);

Setlastvalues (lastvalues, row, fieldnames );
}
}

ReturnNewtable;
}

Private BoolFieldvaluesareequal (Object[] Lastvalues, datarow currentrow,String[] Fieldnames)
{
BoolAreequal= True;

For ( Int I =   0 ; I < Fieldnames. length; I ++ )
{
If (Lastvalues [I] =   Null   |   ! Lastvalues [I]. Equals (currentrow [fieldnames [I])
{
Areequal =   False ;
Break ;
}
}

ReturnAreequal;
}

private datarow createrowclone (datarow sourcerow, datarow newrow, string [] fieldnames)
{< br> foreach ( string Field in fieldnames)
newrow [field] = sourcerow [field];

ReturnNewrow;
}

Private   Void Setlastvalues ( Object [] Lastvalues, datarow sourcerow, String [] Fieldnames)
{
For ( Int I =   0 ; I < Fieldnames. length; I ++ )
Lastvalues [I] = Sourcerow [fieldnames [I];
}

 

 

Datatable. Select

 

Public datatable filltable (string m_where, datatable m_table)
{
Datatable _ temp = m_table.clone ();
Datarow [] _ ROW = m_table.select (m_where );

Foreach (datarow _ r in _ row)
{

_ Temp. Rows. Add (_ R. itemarray );
}
Return _ temp;
}

 

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