我做了一個測驗，應該將用戶的高分存盤在資料庫中，但是我不斷收到一個錯誤，提示“不允許更改“連接字串”
這是我的代碼：
Imports System.Data.OleDb
Public Class Pure
Dim pro As String
Dim connstring As String
Dim command As String
Dim myconnection As OleDbConnection = New OleDbConnection
這是應該將高分添加到訪問資料庫的其余代碼
Private Sub btnSummary_Click(sender As Object, e As EventArgs) Handles btnSummary.Click
pro = "provider=microsoft.ACE.OLEDB.12.0;Data Source=flashcard login.accdb" 'Establish connection with database
connstring = pro
myconnection.ConnectionString = connstring
myconnection.Open() 'Open connection
If lblScore11.Text > lblHighScore.Text Then 'If current socre is greater than high score
lblScore11.Text = lblHighScore.Text
command = " insert into results ([score]) values ('" & lblHighScore.Text & "')"
Dim cmd As OleDbCommand = New OleDbCommand(command, myconnection) 'Establish connection
cmd.Parameters.Add(New OleDbParameter("score", CType(lblHighScore.Text, String)))
End If
End Sub
我在最后添加了這個 try-catch 陳述句（在 if 陳述句中）
Try
cmd.ExecuteNonQuery()
cmd.Dispose()
myconnection.Close()
Catch ex As Exception
MsgBox(ex.Message)
End Try
uj5u.com熱心網友回復：
還有其他問題，但最大的問題是您實際上需要運行查詢：
cmd.ExecuteNonQuery()
此外，這個查詢仍然很容易受到注入問題的影響。這種字串替換對于 SQL 字串是絕對不行的：
values ('" & lblHighScore.Text & "')"
這是一個更好的模式的完整重寫：
Dim connString As String = "provider=microsoft.ACE.OLEDB.12.0;Data Source=flashcard login.accdb"
Private Sub btnSummary_Click(sender As Object, e As EventArgs) Handles btnSummary.Click
If lblScore11.Text <= lblHighScore.Text Then Return
lblHighScore.Text = lblScore11.Text
Using conn As New OleDbConnection(connSstring), _
cmd As New OleDbCommand("INSERT INTO results ([score]) VALUES (?)", conn)
'Use the actual OleDbType that maps to the database column and length here
cmd.Parameters.Add("score", OleDbType.LongVarWChar).Value = lblScore11.Text
conn.Open()
cmd.ExecuteNonQuery()
End Using
End Sub
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