早说你是这样的逻辑
DataTables("表B").datarows.Clear
For Each dr As DataRow In DataTables("表A").DataRows
For i As Integer = 0 To dr("第一列").length - 2
Dim str As String = dr("第一列").Substring(i, 2)
Dim drs As List(of DataRow) = DataTables("表A").Select("第二列 like '%" & str & "%'")
For Each cdr As DataRow In drs
'Dim temp As String = str
'For j As Integer = 3 To dr("第一列").length - i
'Dim s = dr("第一列").Substring(i, j)
'If cdr("第二列") Like "*" & s & "*" Then
' temp = s
'Else
' Exit For
'End If
'Next
If dr("第一列") <> cdr("第二列") Then
Dim ndr As DataRow = DataTables("表B").find("第一列 = '" & dr("第一列") & "' and 第二列 = '" & cdr("第二列") & "'")
If ndr Is Nothing Then
ndr = DataTables("表B").AddNew
ndr("第一列") = dr("第一列")
ndr("第二列") = cdr("第二列")
End If
End If
Next
Next
Next