Question

我有一个数据库，其日期字段“必须”被加密。

要直接从数据库解密，我使用：

    Dim comm As New SqlCommand()
    Dim dt As New DataTable

    comm.Connection = conn ' connection assignment to sql cmd

    With comm
        .CommandText = "SELECT * FROM EMPL ORDER BY EMPL_FIRST_NM ASC"
    End With

    Dim adapter As New SqlDataAdapter(comm)
    adapter.Fill(dt)                    'Fill DT with Query results

    DataGridView1.DataSource = dt       'fill DGV

    Try
        For i As Integer = 0 To dt.Rows.Count - 1
            dt.Rows(i)(1) = clsEncrypt.DecryptData(dt.Rows(i)(1))
            dt.Rows(i)(2) = clsEncrypt.DecryptData(dt.Rows(i)(2))
            And so on..
        Next
    Catch ex As Exception
        MessageBox.Show(e.ToString())
    End Try

我的情况：我需要针对特定日期范围运行WHERE子句。所以，目前在我的DGV，第19栏和第19栏中。 20是BeginDate和EndDate。

如果我需要撤回查询，例如SELECT EMPL_FIRST_NM, EMPL_LAST_NM FROM ???? WHERE BEGINDATE >= 12/21/2013，我需要查看解密的日期值。

我见过类似的东西：

Dim dr As DataRow() dr =

但我不确定我的具体情况。

为了更好的视觉效果：在我填充我的DGV的DataTable中（省略了一些行）

+-----------------------------------------------+
| EMP_ID  EMP_F_NAME  EMP_L_NAME BEG_DT  END_DT |
+-----------------------------------------------+
| 100      John        Doe     20140101 24000101|
| 200      Jake        Locke   20070101 24000101|
| 300      Jim         Slim    20120101 24000101|
| 400      Javier      Suave   20100101 24000101|
+-----------------------------------------------+

Db中的样子：

+------------------------------------------------+
| EMP_ID  EMP_F_NAME  EMP_L_NAME BEG_DT  END_DT  |
+------------------------------------------------+
| ^##$D      @3sAdfq   MR%      $@GFgeh $%@YYWEG |
| K&^D@      54F#$3    L:er@#   %$@YG&^ NH#%HJBR |
| D!@#$      RGER454   M$#Rz    $%T@GERG hYE76F& |
| vfbDW[     DQWR5rf   ~gE5yb   #$!TDDg  mHY6$1* |
+------------------------------------------------+

Answer 1

您可以做的是从服务器获取数据后查询数据表，并使用以下内容解密数据：

Dim DRs as DataRow() = dt.Select("BEGINDATE >= 12/21/2013")

还有许多其他方法，比如使用Linq，但由于我不知道你使用的是什么版本的VB，这适用于所有版本。

Answer 2

所以，我不确定DataRow方法，因为我不确定如何使用它。这部分是我的错，因为我忘记在我的OP中提到我需要实际能够使用这些数据，无论是用于报告还是在DGV中显示数据。

话虽如此，我发现代码导致我使用Structure。我之前从未使用过，所以这可能完全错误 - 但它确实有效。

    'Define a structure to be used as source for data grid view.
Structure mystructure
    Private mDim1 As String
    Private mDim2 As String
    Private mDim3 As String
    Private mDim4 As String
    Private mDim5 As String
    Public Property Dim1() As String
        Get
            Return mDim1
        End Get
        Set(ByVal value As String)
            mDim1 = value
        End Set
    End Property
    Public Property Dim2() As String
        Get
            Return mDim2
        End Get
        Set(ByVal value As String)
            mDim2 = value
        End Set
    End Property
    Public Property Dim3() As String
        Get
            Return mDim3
        End Get
        Set(ByVal value As String)
            mDim3 = value
        End Set
    End Property
    Public Property Dim4() As String
        Get
            Return mDim4
        End Get
        Set(ByVal value As String)
            mDim4 = value
        End Set
    End Property
    Public Property Dim5() As String
        Get
            Return mDim5
        End Get
        Set(ByVal value As String)
            mDim5 = value
        End Set
    End Property
End Structure

现在我们已经准备好接受我们传递给它的值的结构..

Dim lCount As Integer = 0
Dim dt As New DataTable
    With comm
        .CommandText = "SELECT EMPL_ID, EMPL_FIRST_NM, EMPL_LAST_NM, BEG_DT, END_DT FROM EMPL"
    End With

    Dim adapter As New SqlDataAdapter(comm)
    adapter.Fill(dt)                    'Fill DT with Query results

    'read through dataset and write records that meet date criteria to array
    Dim aEmpList(dt.Rows.Count, 5) As String
    Try
        lCount = 0
        For i As Integer = 0 To dt.Rows.Count - 1
            If clsEncrypt.DecryptData(dt.Rows(i)(3)) >= 20130101 Then
                aEmpList(lCount, 0) = clsEncrypt.DecryptData(dt.Rows(i)(0))
                aEmpList(lCount, 1) = clsEncrypt.DecryptData(dt.Rows(i)(1))
                aEmpList(lCount, 2) = clsEncrypt.DecryptData(dt.Rows(i)(2))
                aEmpList(lCount, 3) = clsEncrypt.DecryptData(dt.Rows(i)(3))
                aEmpList(lCount, 4) = clsEncrypt.DecryptData(dt.Rows(i)(4))
                lCount = lCount + 1
            End If
        Next
    Catch ex As Exception
        MessageBox.Show(e.ToString())
    End Try

    'populate structure with aEmpList array
    Dim myarr(dt.Rows.Count) As mystructure
    Try
        For i As Integer = 0 To lCount - 1
            myarr(i) = New mystructure With {.Dim1 = aEmpList(i, 0).ToString, .Dim2 = aEmpList(i, 1).ToString, .Dim3 = aEmpList(i, 2).ToString, .Dim4 = aEmpList(i, 3).ToString, .Dim5 = aEmpList(i, 4).ToString}
        Next
    Catch ex As Exception
        MessageBox.Show(e.ToString())
    End Try

    'use myarr structure as source for datagridview
    DataGridView1.DataSource = myarr      'fill DGV

它很冗长，有点乱，但它确实有效。

总而言之，我在SQL Server 2008 R2数据库中加密了字段。我正在尝试使用SELECT * FROM Table WHERE DATE >= 20130101恢复记录（仅用于示例）。好吧，当日期字段被加密时，不可能传递WHERE子句并返回数据。因此，我必须将其恢复，解密并将其存储在数据表中。然后我创建了一个数组aEmpList，并用解密的数据字段填充它。我最终加载了带有数据表解密aEmpList数组的结构，并将其用作DGV的数据源。

有人可以发现这很有用。

将数据加载到DataTable并解密，然后对其运行查询

2 个答案: