主题：比较两列的相似性

Dim flag As Boolean = False

For Each dr As DataRow In DataTables("数据库1").datarows

    Dim val As String = dr("B列")

    Dim drr As DataRow  = Nothing

    If val > "" Then

        drr  =  DataTables("数据库1").find("A列='" & val.SubString(0,2)  & "'")

    End If

    If drr IsNot Nothing Then

        dr("重复标记")="有重复"

        flag = True

    Else

        dr("重复标记")= Nothing

    End If

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