多步 OLE DB 操作产生错误。 C#/MS Access [重复]

Question

在你们告诉我这是重复之前，你们应该知道我已经完成了几乎所有我能找到的答案。但我仍然无法解决这个问题。 我已尝试在 Computer\HKEY_CLASSES_ROOT\CLSID 中为所有 OLEDB 添加注册表值，如下所示：-

Value Name: OLEDB_SERVICES Data Type: REG_DWORD Value: 0xFFFFFFFF

-> 我尝试从连接字符串和数据库中的密码中删除特殊字符。 -> 我试过使用 Integrated Security=True , Integrated Security=SSPI, 持久安全信息=True

我的连接字符串是：- `

<appSettings>
<add key="Con" value="Provider=Microsoft.ACE.OLEDB.12.0;Jet OLEDB:Database Password=Preeya1 Data Source=C:\Users\Aqore-User\Desktop\Accounting\AccountingDbEnc.accdb"/>
</appSettings>

`

我的代码是：-

OleDbDataAdapter da = new OleDbDataAdapter
("Select * from [Users] where " +"[User]='"+UsernameTextbox.Text+"' and " +
"[Password]='"+PasswordTextbox.Text+"'", conn);
DataSet ds = new DataSet();

da.Fill(ds); <<--THIS IS WHERE ERROR OCCURS

if (ds.Tables[0].Rows.Count > 0)
{
MainForm mf = new MainForm();
mf.Show();
this.Hide();
}

在 AccessDB 中，用户的数据类型是“长文本”，密码是“短文本”

整个例外：-

System.Data.OleDb.OleDbException
  HResult=0x80040E21
  Message=Multiple-step OLE DB operation generated errors. Check each OLE DB status value, if available. No work was done.
  Source=System.Data
  StackTrace:
   at System.Data.OleDb.OleDbConnectionInternal..ctor(OleDbConnectionString constr, OleDbConnection connection)
   at System.Data.OleDb.OleDbConnectionFactory.CreateConnection(DbConnectionOptions options, DbConnectionPoolKey poolKey, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningObject)
   at System.Data.ProviderBase.DbConnectionFactory.CreateConnection(DbConnectionOptions options, DbConnectionPoolKey poolKey, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningConnection, DbConnectionOptions userOptions)
   at System.Data.ProviderBase.DbConnectionFactory.CreateNonPooledConnection(DbConnection owningConnection, DbConnectionPoolGroup poolGroup, DbConnectionOptions userOptions)
   at System.Data.ProviderBase.DbConnectionFactory.TryGetConnection(DbConnection owningConnection, TaskCompletionSource`1 retry, DbConnectionOptions userOptions, DbConnectionInternal oldConnection, DbConnectionInternal& connection)
   at System.Data.ProviderBase.DbConnectionInternal.TryOpenConnectionInternal(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource`1 retry, DbConnectionOptions userOptions)
   at System.Data.ProviderBase.DbConnectionClosed.TryOpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource`1 retry, DbConnectionOptions userOptions)
   at System.Data.ProviderBase.DbConnectionInternal.OpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory)
   at System.Data.OleDb.OleDbConnection.Open()
   at System.Data.Common.DbDataAdapter.FillInternal(DataSet dataset, DataTable[] datatables, Int32 startRecord, Int32 maxRecords, String srcTable, IDbCommand command, CommandBehavior behavior)
   at System.Data.Common.DbDataAdapter.Fill(DataSet dataSet, Int32 startRecord, Int32 maxRecords, String srcTable, IDbCommand command, CommandBehavior behavior)
   at System.Data.Common.DbDataAdapter.Fill(DataSet dataSet)
   at Accounting_Project.Project.LoginForm.LoginButton_Click(Object sender, EventArgs e) in C:\Users\Aqore-User\source\repos\Accounting Project\Accounting Project\Project\LoginForm.cs:line 45
   at System.Windows.Forms.Control.OnClick(EventArgs e)
   at System.Windows.Forms.Button.OnClick(EventArgs e)
   at System.Windows.Forms.Button.OnMouseUp(MouseEventArgs mevent)
   at MetroFramework.Controls.MetroButton.OnMouseUp(MouseEventArgs e)
   at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
   at System.Windows.Forms.Control.WndProc(Message& m)
   at System.Windows.Forms.ButtonBase.WndProc(Message& m)
   at System.Windows.Forms.Button.WndProc(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
   at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
   at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg)
   at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(IntPtr dwComponentID, Int32 reason, Int32 pvLoopData)
   at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)
   at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)
   at System.Windows.Forms.Application.Run(Form mainForm)
   at Accounting_Project.Program.Main()

任何帮助将不胜感激，任何可以帮助我理解和解决此问题的文章或指导都将不胜感激。

注意：- 我拥有所有 Microsoft Access 驱动程序 12、14 和 16，但选择使用 12，因为它在我看到的教程中使用。我正在使用 Access 2016 和 Visual Studio 2017。

Answer 1

1. 始终为传入的值使用参数。
2. OleDb 的参数未命名，它们是基于序数/位置的。
3. 根据架构中的约束更新每个参数的长度。
4. （与错误无关） - 切勿以纯文本形式存储密码。改为存储密码的单向哈希。

如果这不能解决您的问题，请发布完整的异常、堆栈跟踪和类型。

const string sqlStatement = "Select * from [Users] WHERE [User]= ? AND [Password]= ?";

OleDbDataAdapter da = new OleDbDataAdapter();
OleDbCommand command = new OleDbCommand(sqlStatement, conn);
command.Parameters.Add(new OleDbParameter("@username", OleDbType.LongVarChar, 200)).Value = UsernameTextbox.Text;
command.Parameters.Add(new OleDbParameter("@password", OleDbType.VarChar, 100)).Value = PasswordTextbox.Text;

da.SelectCommand = command;
DataSet ds = new DataSet();
da.Fill(ds);