Question

我遇到了与MS Access的OleDb连接问题。这一行引发了错误：

command1.ExecuteNonQuery();

下一部分是我的代码：

if (textBox.Text.Length != 6) return;
{
    cmd.CommandText = ("SELECT last_name +', '+ first_name from name where id =@Name");
    cmd.Parameters.Add(new SqlParameter("Name", textBox.Text.Replace(@"L", "")));
    cmd.CommandType = CommandType.Text;
    cmd.Connection = DBConnection;

    returnValue = cmd.ExecuteScalar() + "\t " + textBox.Text.Replace(@"L", "");

    DBConnection.Close();

    OleDbConnection connection1 = new OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=|DataDirectory|\\Registration.accdb");
    OleDbCommand command1 = new OleDbCommand();
    command1.CommandText = "UPDATE Table SET ID=@ID, Name=@Name, TimeIn=@TimeInAM, TimeOut=@TimeOutAM";
    command1.Parameters.AddWithValue("@ID", returnValue);
    connection1.Open();
    command1.ExecuteNonQuery();
    connection1.Close();

    Staff_Register(returnValue, e);
}

Answer 1

您没有将connection1与command1相关联，这就是您获得例外的原因。

command1.CommandText = "UPDATE Table SET ID=@ID, Name=@Name, TimeIn=@TimeInAM, TimeOut=@TimeOutAM";
command1.Parameters.AddWithValue("@ID", returnValue);
command1.Connection = connection1; // missing this
connection1.Open();

还要考虑将using语句与连接和命令一起使用，以确保处理连接对象。

Answer 2

在调用ExecuteNonQuery（）之前将连接对象分配给命令对象，如下所示：

command1.Connection=connection1 ;

ExecuteNonQuery- Connection属性尚未初始化

2 个答案: