使用 VB.NET 的 Windows 服务不起作用？

Question

我的程序应该做什么：我的目标是创建一个 Windows 服务，它充当多个 SQL 数据库之间的中介。总共有 3 个不同的表在 3 个不同的服务器上。详细地说，当这个服务运行时，它应该监督“表 1”中的数据，并定期（每 1 分钟）将其复制到“表 2”。但棘手的部分是它不能粘贴重复记录，必须检查 "Table2" 的 ID 字段并验证是否没有粘贴具有相同 ID 的相同记录。I've added a diagram for understanding purposes of what my goal is

我做了什么：到目前为止，我已经完全开发了代码，但问题是它只从一个表中复制数据（根据我所附的图表，特别是“NOR_LABOR”）到“MES_DEV”数据库中的“DEV_Test_Nor_Data”（con1 到 con2）。根据图con1、con3、con4分别是表“NOR_LABOR”、“SETTER_LABOR”和“wrap_labor”。 con2 是“MES_DEV”数据库的目的地。

谁能弄清楚为什么其他表的数据（con3 to con2 & con4 to con2）不会复制？

我的代码 - 数据收集器

Imports System.Configuration
Imports System.Data.SqlClient

Public Class DataCollector

    Dim con1, con2, con3, con4 As New SqlConnection
    Dim timer1 As Timers.Timer
    Dim p_oConn As New Wisys.AllSystem.ConnectionInfo
    Protected Overrides Sub OnStart(ByVal args() As String)

        con1 = New SqlConnection("Data Source=NORMAC-CTMS\SQLEXPRESS;Database=Normac Data;Integrated Security=true")
        con1.Open()
        con2 = New SqlConnection("Data Source=STLEDGSQL01;Database=MES_DEV;Integrated Security=true")
        con2.Open()
        con3 = New SqlConnection("Data Source=201706-SETTER1\SQLEXPRESS;Database=Edge;Integrated Security=true")
        con3.Open()
        con4 = New SqlConnection("Data Source=PRINTER\SQLEXPRESS;Database=Wrapper Data;Integrated Security=true")
        con4.Open()

        timer1 = New Timers.Timer()
        timer1.Interval = 5000
        AddHandler timer1.Elapsed, AddressOf OnTimedEvent
        timer1.Enabled = True
        FileIO.WriteLog("Service has started")

    End Sub

    Protected Overrides Sub OnStop()
        timer1.Enabled = False
        FileIO.WriteLog("Service has stopped")
        con1.Close()
        con2.Close()
        con3.Close()
        con4.Close()
    End Sub


    Private Sub OnTimedEvent(obj As Object, e As EventArgs)

        Dim cmd1, cmd2, cmd3 As SqlCommand

        'Connecting the Normac Data table
        Dim da1 As SqlDataAdapter = New SqlDataAdapter("select ID, trx_date, work_order, department, work_center, operation_no, operator, total_labor_hours, feet_produced, item_no, posted, labor_feet_produced from NOR_LABOR", con1)
        Dim cb1 As SqlCommandBuilder = New SqlCommandBuilder(da1)
        Dim dt1 As DataTable = New DataTable()
        da1.Fill(dt1)

        'Connecting the Setter_Labor table
        Dim da2 As SqlDataAdapter = New SqlDataAdapter("select ID, trx_date, work_order, department, work_center, operation_no, operator, total_labor_hours, labor_feet_produced, item_no, posted from Setter_Labor", con3)
        Dim cb2 As SqlCommandBuilder = New SqlCommandBuilder(da2)
        Dim dt2 As DataTable = New DataTable()
        da2.Fill(dt2)

        'Connecting the Wrap_Labor table
        Dim da3 As SqlDataAdapter = New SqlDataAdapter("select ID, trx_date, work_order, Department, work_center, operation_no, operator, total_labor_hrs, job_start, job_end, qty_ordered, qty_produced, item_no, lot_no, default_bin, posted, wrapped, total_shift_hrs, check_emp, machine, operation_complete from wrap_labor", con4)
        Dim cb3 As SqlCommandBuilder = New SqlCommandBuilder(da3)
        Dim dt3 As DataTable = New DataTable()
        da3.Fill(dt3)


        Dim i, j, k As Integer

        'Inserting into DEV_Test_Nor_Data table
        For Each dr As DataRow In dt1.Rows

            cmd1 = New SqlCommand("Insert into DEV_Test_Nor_Data values('" & dr(0) & "','" & dr(1) & "','" & dr(2) & "','" & dr(3) & "','" & dr(4) & "','" & dr(5) & "','" & dr(6) & "','" & dr(7) & "','" & dr(8) & "','" & dr(9) & "','" & dr(10) & "','" & dr(11) & "')", con2)
            i = cmd1.ExecuteNonQuery()


        Next

        'Inserting into DEV_Test_Set_Lbr table
        For Each dr As DataRow In dt2.Rows

            cmd2 = New SqlCommand("Insert into DEV_Test_Set_Lbr values('" & dr(0) & "','" & dr(1) & "','" & dr(2) & "','" & dr(3) & "','" & dr(4) & "','" & dr(5) & "','" & dr(6) & "','" & dr(7) & "','" & dr(8) & "','" & dr(9) & "','" & dr(10) & "')", con2)
            j = cmd2.ExecuteNonQuery()

        Next

        'Inserting into DEV_Test_Wrp_Lbr table
        For Each dr As DataRow In dt3.Rows

            cmd3 = New SqlCommand("Insert into DEV_Test_Wrp_Lbr values('" & dr(0) & "','" & dr(1) & "','" & dr(2) & "','" & dr(3) & "','" & dr(4) & "','" & dr(5) & "','" & dr(6) & "','" & dr(7) & "','" & dr(8) & "','" & dr(9) & "','" & dr(10) & "','" & dr(11) & "','" & dr(12) & "','" & dr(13) & "','" & dr(14) & "','" & dr(15) & "','" & dr(16) & "','" & dr(17) & "','" & dr(18) & "','" & dr(19) & "','" & dr(20) & "')", con2)
            k = cmd3.ExecuteNonQuery()

        Next


        da1.Update(dt1)
        cmd1.Dispose()
        dt1.Dispose()
        da1.Dispose()

        da2.Update(dt2)
        cmd2.Dispose()
        dt2.Dispose()
        da2.Dispose()

        da3.Update(dt3)
        cmd3.Dispose()
        dt3.Dispose()
        da3.Dispose()

    End Sub
End Class

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Answer 1

看看这是否有帮助。可能参数化查询是您的全部问题。

Public Class DataCollector

    'Question text said one minute
    Private timer1 As New Timers.Timer(60000)

    Protected Overrides Sub OnStart(ByVal args() As String)
        AddHandler timer1.Elapsed, AddressOf OnTimedEvent
        timer1.Enabled = True
        FileIO.WriteLog("Service has started")
    End Sub

    Protected Overrides Sub OnStop()
        timer1.Enabled = False
        FileIO.WriteLog("Service has stopped")
    End Sub

    Private Sub OnTimedEvent(obj As Object, e As EventArgs)
        ' DEV_Test_Nor_Data Table
        ProcessOneTable("DEV_Test_Nor_Data", 12,
            "Data Source=NORMAC-CTMS\SQLEXPRESS;Database=Normac Data;Integrated Security=true", 
            "SELECT ID, trx_date, work_order, department, work_center, operation_no, operator, total_labor_hours, feet_produced, item_no, posted, labor_feet_produced FROM NOR_LABOR"
        )

        ' DEV_Test_Set_Lbr Table
        ProcessOneTable("DEV_Test_Set_Lbr", 11, 
            "Data Source=201706-SETTER1\SQLEXPRESS;Database=Edge;Integrated Security=true",
            "SELECT ID, trx_date, work_order, department, work_center, operation_no, operator, total_labor_hours, labor_feet_produced, item_no, posted from Setter_Labor"
        )

        ' DEV_Test_Wrp_Lbr Table
        ProcessOneTable("DEV_Test_Wrp_Lbr", 21,
            "Data Source=PRINTER\SQLEXPRESS;Database=Wrapper Data;Integrated Security=true",
            "SELECT ID, trx_date, work_order, Department, work_center, operation_no, operator, total_labor_hrs, job_start, job_end, qty_ordered, qty_produced, item_no, lot_no, default_bin, posted, wrapped, total_shift_hrs, check_emp, machine, operation_complete from wrap_labor"
        )
    End Sub

    Private EdgeConnStr As String = "Data Source=STLEDGSQL01;Database=MES_DEV;Integrated Security=true"

    Private Sub ProcessOneTable(destTableName As String, ParameterCount As Integer, sourceConnectionString AS String, sourceSql As String)
        Dim data As New DataTable()
        Using sourceConn As New SqlConnection(sourceConnectionString), _
              da As New SqlDataAdapter(sourceSql, sourceConn)
            da.Fill(data)
        End Using

        Dim paramList As String = String.Join(",", Enumerable.Range(0, ParameterCount).Select(Function(p) $"@p{p}"))
        ' Assumes first parateter (@p0) is always the ID.
        Dim sql As String = $"INSERT INTO {destTableName} SELECT {paramList} WHERE NOT EXISTS(SELECT ID FROM {destTableName} WHERE ID = @p0)"
        Using cn As New SqlConnection(EdgeConnStr), _
              cmd As New SqlCommand(sql, cn)

            For i As Integer = 0 To ParameterCount - 1
                cmd.Parameters.Add($"@p{i}", SqlDbType.VarChar)
            Next i
        
            cn.Open()
            For Each dr As DataRow In data.Rows
                For i As Integer = 0 to ParameterCount - 1
                    cmd.Parameters(i).Value = dr(i)
                Next i
                cmd.ExecuteNonQuery()
            Next dr
        End Using
    End Sub
End Class

听起来您还需要担心合并数据，但无论如何都要从这个开始；它修复了原始代码中的HUGE GAPING SECURITY ISSUE，并将代码的重要部分隔离到尽可能小的方法大小。这将使重构只是该部分变得更容易，也可以担心哪些 ID 可能已经存在......但我会让你自己先尝试一下（提示：INSERT + SELECT + WHERE NOT EXISTS() all in相同的查询）