Vb.net Visual basic-增加分数

我终于找到了要显示的消息框！但是现在我的代码在数据库中没有增加，有人能帮我吗

提前感谢

在修复您的输入错误（登录文本框后面的空格和检索到的字段名称）后，您仍然无法执行更新数据库的sql文本

如果WHERE条件找不到任何要更新的内容，则可以简化代码，从而理解更新查询没有任何效果。此外，在尝试执行MySqlCommand时保持MySqlDataReader打开将触发MySql NET connector中的错误。（无法使用datareader正在使用的连接）。我们可以尝试在对ExecuteReader的一次调用中执行这两条语句，使用分号分隔每个命令，当然，还可以使用参数而不是字符串连接

    Private Sub Button4_Click(sender As Object, e As EventArgs) Handles Button4.Click
    Dim READER As MySqlDataReader
    Dim Query As String
    Dim connection As MySqlConnection
    Dim COMMAND As MySqlCommand
    Dim item As Object
    Try
        item = InputBox("What is the item?", "InputBox Test", "Type the item here.")
        If item = "shoe" Then
            Dim connStr As String = ""
            Dim connection As New MySqlConnection(connStr)
            connection.Open()
            Query = "select * from table where username= '" & Login.txtusername.Text & " '"
            COMMAND = New MySqlCommand(Query, connection)
            READER = COMMAND.ExecuteReader
            If (READER.Read() = True) Then
                Query = "UPDATE table set noOfItems = noOfItems+1, week1 = 'found' where username= '" & Login.txtusername.Text & "'"
                Dim noOfItems As Integer
                Dim username As String
                noOfItems = READER("noOfItems") + 1
                username = READER("username")
                MessageBox.Show(username & "- The number of items you now have is: " & noOfGeocaches)
            End If
        Else
            MsgBox("Unlucky, Incorrect item. Please see hints. Your score still remains the same")

        End If
    Catch ex As Exception
        MessageBox.Show("Error")
    End Try

---

您的select查询中有输入错误。您正在用户名值后添加一个空格。顺便说一句，如果您希望sql字符串对您的表产生任何影响，那么它应该由MySqlCommand执行。这导致了另一个问题。datareader打开时无法使用命令。另外，为什么要增加名为noOfItems的字段，然后尝试显示noOfGeocaches的值？您好@Steve我感谢您的帮助！我已经对查询输入进行了排序！并将变量更改为noOfItems（认为这是一个输入错误）。但是，数据库中仍然没有增量。我将进一步研究mysqlcommand，如果您有任何想法，关于如何解决这个问题，请随意更正我的代码：）@Steve如果我切换这两个查询，我注意到数据库会增加值，但是消息框看起来并不友好！我真的很感激这一点，它就像一个魅力，我会花时间理解这段代码：）而且我用dim替换了所有的using，仍然工作得很好。。我在使用时遇到了一个错误function@mr-高效地格式化你的代码？也许它会编译。

' Prepare the string for both commands to execute
Query = "UPDATE table set noOfItems = noOfItems+1, " & _ 
        "week1 = 'found' where username= @name; " & _
        "SELECT noOfItems FROM table WHERE username = @name"

' You already know the username, don't you?
Dim username = Login.txtusername.Text

' Create the connection and the command inside a using block to
' facilitate closing and disposing of these objects.. exceptions included
Using connection = New MySqlConnection(connStr)
Using COMMAND = New MySqlCommand(Query, connection)
    connection.Open()

    ' Set the parameter value required by both commands.
    COMMAND.Parameters.Add("@name", MySqlDbType.VarChar).Value = username

    ' Again create the reader in a using block
    Using READER = COMMAND.ExecuteReader
        If READER.Read() Then
            Dim noOfItems As Integer
            noOfItems = READER("noOfItems")
            MessageBox.Show(username & "- The number of items you now have is: " & noOfItems )
        End If
   End Using
End Using
End Using