在循环后提交更改-仅保存最后一条记录

下面的代码可以工作,但它只保存循环中的最后一条记录,我不知道为什么。我认为 Submitchanges() 在正确的位置,在循环的末尾。有人能告诉我怎么了吗?谢谢

Sub POPULATE_CHAIN()

    Dim newChain As New CHAIN
    Dim dpSTRIKE As Integer

    'get list of Options Contracts
    Dim lstOPT = From Z In DATA.OPTIONs, X In DATA.UDLies
                 Where X.UDLY_SYM = Z.UDLY_SYM
                 Select Z.CONTRACT, Z.STRIKE_GAP, X.UDLY_LAST

    Dim dctOPT = lstOPT.ToDictionary(Function(Z) Z.CONTRACT)

    For Each key In dctOPT.Keys

        For COUNT = 1 To 5
            dpSTRIKE = 1850 + 5 * COUNT
            Dim lkup = From Z In DATA.CHAINs
                       Select Z
            Dim RCD_EXISTS As Boolean = lkup.Any(Function(Z) Z.CONTRACT = dctOPT(key).CONTRACT And Z.P_C = "C" And Z.STRIKE = dpSTRIKE)

            If RCD_EXISTS = False Then
                newChain.CONTRACT = dctOPT(key).CONTRACT
                newChain.P_C = "C"
                newChain.STRIKE = dpSTRIKE
                DATA.CHAINs.InsertOnSubmit(newChain)
            Else
                newChain.CONTRACT = dctOPT(key).CONTRACT
                newChain.P_C = "C"
                newChain.STRIKE = dpSTRIKE
            End If

        Next
    Next
    DATA.SubmitChanges()
End Sub