循环后提交更改 - 仅保存最后一条记录

Question

下面的代码可以运行，但是它只保存了循环中的最后一条记录，我不明白为什么。我认为 Submitchanges() 在正确的位置，在循环的末尾。有人可以告诉我出了什么问题吗？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

Answer 1

Dim newChain As New CHAIN

应该在Fore Each里面，正好在second for里面。因为它是在循环外声明的，所以它将与 table 分离并再次附加到 table。所以它只会被插入到最后一行。

循环后提交更改 - 仅保存最后一条记录

Submitchanges after a loop - only last record saved

vb.net

loops

linq-to-sql

submitchanges