Question

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。

这是一款培训应用。用户必须先注册才能创建帐户。

然后他们使用他们的帐户报名参加课程。

首先，代码会检查此用户是否已注册特定类。

如果不是，请先注册用户。如果是，请通知该用户他/她已经注册。

这位有效。

如果用户尚未签名并且正在尝试注册，请检查是否仍有座位可用。如果是，请注册用户。如果没有更多席位可用，请通过插入名为tblWaitinglist的表格将用户置于等待列表中。

到目前为止，每当我尝试插入一条新记录时，它说，课程已满，用户正在等候名单。

事实并非如此。班级完全是空的。

总共有45个席位。

到目前为止，所有座位都可用。

我到底做错了什么？

甚至没有插入等候名单。它只是给出了它所做的信息。

请参阅下面的代码，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

Answer 1

看起来你永远不会将SeatsAvailable设置为零以外的任何东西。您的变量可能就是您想要查看的内容。

INSERT失败是另一个问题。

将插入记录到错误的表中。任何想法为什么以及如何解决它？

1 个答案: