Asp.net 记录插入到错误的表中。你知道为什么以及如何修复它吗？

这对我来说很奇怪

我试图获取此代码的存储过程版本，但没有成功

这是一个培训应用程序。用户必须先注册才能创建帐户

然后他们用自己的账户注册上课

首先，代码检查此用户是否已注册特定类

如果没有，请向用户注册。如果是，则通知该用户他/她已注册

这个钻头有效

如果用户尚未注册并且正在尝试注册，请检查是否还有可用的座位。如果是，请向用户注册。如果没有更多的座位可用，将用户插入名为tblWaitinglist的表中，将其放入等待列表

到目前为止，每次我尝试插入一条新记录时，它都会说，类已满，用户正在等待列表中

事实并非如此。类是完全空的

总共有45个座位

到目前为止，所有座位都有空

我到底做错了什么

它甚至没有插入到等待列表中。它只是传递了它确实做到了的信息

请看下面我的代码，并提前感谢

Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs)
    Dim username = Session("Username")
    Dim connStr As String = ConfigurationManager.ConnectionStrings("DBConnectionString").ConnectionString
    Dim conn As New SqlConnection(connStr)
    conn.Open()
    Try

        Dim s As String
        Dim counter As Integer

        'If user already registered for a class, alert user
        s = "SELECT Count(*) FROM tblTrainings WHERE Username = '" & username & "' AND CourseID = " & Request.QueryString("cosId") & "  AND LocationID = " & Request.QueryString("locid") & " AND dateId = " & Request.QueryString("iddate") & ""
        'Response.Write(s)
        'Response.End()
        Dim connSt As String = ConfigurationManager.ConnectionStrings("DBConnectionString").ConnectionString
        Dim connc As New SqlConnection(connSt)
        Dim cmdc As New SqlCommand(s, connc)
        connc.Open()
        cmdc.ExecuteNonQuery()
        counter = cmdc.ExecuteScalar()


        '   Now let's see if we found existing record of registration
        If counter = 0 Then 'User has not registered for this training. In that case, check to see there are still seats available.
            Dim SeatsAvailable As Integer
            SeatsAvailable = 0

            s = " SELECT SeatsAvailable = (Select Seating_Capacity  - (Select count(*) from tblTrainings where courseId = @cosId) from tblLocations WHERE LocationId = @Locid)"
            'Response.Write(s)
            'Response.End()
            Dim cmdB As New SqlCommand(s, conn)
            cmdB.Parameters.AddWithValue("@cosID", Request.QueryString("cosId"))
            cmdB.Parameters.AddWithValue("@locID", Request.QueryString("locid"))
            cmdB.ExecuteNonQuery()


            If SeatsAvailable > 0 Then 'Ok there are still seats available. Sign this user up.
                s = "INSERT INTO tblTrainings (CourseId, LocationId, dateId,username) VALUES (@CosID, @LocID, @dat, @Username)"
                Dim cmd = New SqlCommand(s, conn)
                cmd.Parameters.AddWithValue("@cosID", Request.QueryString("cosId"))
                cmd.Parameters.AddWithValue("@locID", Request.QueryString("locid"))
                cmd.Parameters.AddWithValue("@dat", Request.QueryString("iddate"))
                cmd.Parameters.AddWithValue("@UserName", username)
                'Response.Write(s)
                'Response.End()
                cmd.ExecuteNonQuery()
                Dim cmdGetKey As New SqlCommand("SELECT @@IDENTITY", conn)
                Dim skey As Integer = cmdGetKey.ExecuteScalar()
                Session("TrainingId") = skey
                conn.Close()
                confirmRegistraction()
                Label1.ForeColor = System.Drawing.Color.Red
                Label1.Text = "Congratulations! You have been registered for this class. Please check your email inbox for details"
            Else 'No seats remain. So, put user on waiting list
                s += "INSERT INTO tblWaitingList (CourseId, LocationId, dateId,username) VALUES (@CosID, @LocID, @dat, @Username)"
                Dim cmd = New SqlCommand(s, conn)
                cmd.Parameters.AddWithValue("@cosID", Request.QueryString("cosId"))
                cmd.Parameters.AddWithValue("@locID", Request.QueryString("locid"))
                cmd.Parameters.AddWithValue("@dat", Request.QueryString("iddate"))
                cmd.Parameters.AddWithValue("@UserName", username)
                'Response.Write(s)
                'Response.End()
                cmd.ExecuteNonQuery()
                Dim cmdGetKey As New SqlCommand("SELECT @@IDENTITY", conn)
                Dim skey As Integer = cmdGetKey.ExecuteScalar()
                Session("TrainingId") = skey
                conn.Close()
                onWaitingList()
                'Display some feedback to the user to let them know it was processed
                Label1.ForeColor = System.Drawing.Color.Red
                Label1.Text = "Sorry, but this class is full. However, you have been placed on waiting list."
            End If

        Else
            'Alert user that s/he has already registered for this class
            Label1.ForeColor = System.Drawing.Color.Red
            Label1.Text = "You have already signed up for this training."
        End If

    Catch

        'If the message failed at some point, let the user know
        Label1.ForeColor = System.Drawing.Color.Red
        Label1.Text = "Your record failed to save, please try again."

    End Try
End Sub

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看起来您从未将SeatAvailable设置为零以外的任何值。您的s变量可能就是您想要查看的

---

插入失败是另一个问题。

您应该使用

或
try/catch/finally
来清理代码中的资源。问题似乎是
SeatsAvailable
始终为0。你试过调试吗？也许是因为你从来没有给它分配过0以外的任何东西
s=“SELECT SeatsAvailable[…]”
不会神奇地将查询的输出写入名为
seatsailable的变量中，您必须从查询结果中分配它。不幸的是，您调用了
ExecuteNonQuery（）
，这不允许您这样做。首先@CodeCaster，很抱歉代码和文本堆积如山。有时，很难说什么时候足够就足够了，因为总是会出现并说，“没有足够的信息或代码”来回答您的问题，SeatsAvailable并不总是0。如果我在SSMS上运行该查询，它将输出正确的值，在本例中为45。同样，正如前面所说的，即使它说，你们已经被放到了waitinglist中，一条记录也应该被插入到waitinglist表中。未向表中插入任何内容。您的程序未在SSMS中运行查询。它也不会将查询结果分配给任何对象。设置断点。检查
seatsavaailable
变量。看，它总是0。请看一下
ExecuteScalar（）
method.FYI，这并不是真正使用存储过程，因为您仍然在使用内嵌式SQL。@Dourglas和CodeCaster，实际上我在一件事上错了。正在将记录插入WaitingList表，是，消息是正确的。但问题是，当SeatsAvailable大于0时，它应该插入到训练表中。我的逻辑错了吗？我现在开始工作了。我删除了SeatsAvailable=0，改为使用：SeatsAvailable=cmdB.ExecuteScalar（），它可以工作。你们是最棒的。非常感谢。