vb.net - 使用数据集结果执行非查询问题

Question

我有一个有趣的项目，其中涉及 VB.net winform 应用程序。此应用程序将数据集用于表单。Shift_Log (SL)、Problem_Log (PL) 和 Service_Request (SR) 将影响三个表。如果用户更改（SL）上的日志日期，使（PL）不再与错误时间一致。我需要从 (PL) 和 (SR) 表中删除外键。我还没有测试过这个。在我做之前我有几个问题。

1. 如果在第二个 update (SR)sql 命令中没有要更新的记录怎么办？

2. 执行此操作后是否需要刷新数据集。

    Public Function UPD_PL_Check(ByVal Shift_Key As String, ByVal SL_Begin As DateTime, SL_End As DateTime) As Integer
   
    ' Get rows from Laser Status Info
    Dim query As String = "SELECT Status_Key FROM [dbo].[Laser_Status_Info]  " &
                " WHERE [Shift_FKey] = " & Shift_Key &
                " AND [Err_time] NOT Between " & SL_Begin & " AND " & SL_End & ";"
   
    Dim dt As DataTable = New DataTable()
    Using conn As SqlConnection = New SqlConnection(My.Settings.LaserMaintLogConnectionString)
        conn.Open()
        Try
            Dim da As SqlDataAdapter = New SqlDataAdapter(query, conn)
            da.Fill(dt)
        Catch ex As Exception
            MessageBox.Show("Error occured! : " & ex.Message)
        Finally
            conn.Close()
        End Try
    End Using
   
    Dim rowsAffected As Integer = dt?.Rows.Count
   
    If rowsAffected = 0 Then Return rowsAffected
   
    ' Update the Problem log
    For Each i In dt?.Rows
        Using conn As SqlConnection = New SqlConnection(My.Settings.LaserMaintLogConnectionString)
            conn.Open()
            Dim Status_Key As String = dt.Rows(i)("Status_Key")
            Try
                Dim PL_query As String =
                 "UPDATE [dbo].[Laser_Status_Info] " &
                 "   SET [Shift_FKey] = '' " &
                 " WHERE [Status_Key] = '" & Status_Key & "';"
                Using Cmd As New SqlCommand(query, conn)
                    rowsAffected = Cmd.ExecuteNonQuery()
                End Using
   
            Catch ex As Exception
                MessageBox.Show("Error occured! : " & ex.Message)
            End Try
   
            ' Update Service request
            Try
                Dim PL_query As String =
                 "UPDATE [dbo].[Laser_Maint_Log] " &
                 "   SET [SR_Shift_Key] = '' " &
                 " WHERE [SR_Status_Key] = '" & Status_Key & "';"
                Using Cmd As New SqlCommand(query, conn)
                    rowsAffected = Cmd.ExecuteNonQuery()
                End Using
            Catch ex As Exception
                MessageBox.Show("Error occured! : " & ex.Message)
            End Try
            conn.Close()
        End Using
    Next
   
    Return rowsAffected
   

   结束功能

标签： vb.netwinforms