主题：去重复

Dim Cols1() As String = {"第一列","第二列","第三列"}
Dim Cols2() As String = {"第一列","第二列","第三列"}
For Each dr1 As DataRow In DataTables("表A").Select("")
    Dim dr2 As DataRow = DataTables("表B").AddNew()
    For i As Integer = 0 To Cols1.Length -1
        dr2(Cols2(i)) = dr1(Cols1(i))
    Next
Next

请问这段怎么出重复