c# - 文本框的 AccesDB 值

Question

我正在尝试从 Access 数据库获取一个值到 WPF 中的文本框。表名是 Member，列名是 MemberID。我尝试了以下代码，但在“OleDbDataReader reader = command.ExecuteReader();”行出现异常

The exception is: An unhandled exception of type 'System.Data.OleDb.OleDbException' occurred in System.Data.dll. Additional information: Data type mismatch in criteria expression.

代码:

    private void showInfoBtn_Click(object sender, RoutedEventArgs e)
    {
        int index = 1;

        string connection = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:/Users/Cvenko/Desktop/Library.accdb";

        using (OleDbConnection conn = new OleDbConnection(connection))
        {
            conn.Open();

            OleDbCommand command = new OleDbCommand("SELECT FirstName FROM Member WHERE MemberID = '" + index + "'", conn);
            OleDbDataAdapter adapter = new OleDbDataAdapter(command);

            AddMember m = new AddMember();
            m.Show();

            OleDbDataReader reader = command.ExecuteReader();
            if (reader.HasRows)
            {
                reader.Read();
                m.nameTxt.Text = reader.GetString(1);
            }

            conn.Close();
            command.Dispose();
            adapter.Dispose();
        }
    }

Answer 1

我很怀疑 MemberID 是文本，所以你不应该使用引号:

"SELECT FirstName FROM Member WHERE MemberID = " + index