string insertSQL = "INSERT INTO TBLSTUDENTS (NUMBER,NAME,PASSWORD) VALUES (@NUMBER,@NAME,@PASSWORD)";

            mycmd = new OleDbCommand(insertSQL, myconnection);

           
mycmd.Parameters.Add("@NUMBER", OleDbType.VarChar, 8).Value = "爱你";

           
mycmd.Parameters.Add("@NAME", OleDbType.VarChar, 10).Value = "不变";

           
mycmd.Parameters.Add("@PASSWORD", OleDbType.VarChar, 10).Value = "一万年";

            //打开链接

            mycmd.Connection.Open();

            try

            {

                mycmd .ExecuteNonQuery();

                //执行查询

            }

            catch(Exception e1)

            {

               
MessageBox .Show(e1.ToString(),"添加发生错误，请检查参数是否合法");

                mycmd .Connection.Close();

                return;

            }

            mycmd .Connection.Close();



这样的一段代码，为什么执行时总是说我的@NUMBER没有定义哩，真搞不懂哩，我找不出来啊,（以上所有列的类型均为VARCHAR）

你这种方法没用过，不知道原因，不过可以你这段代码可以改为：
            string number = null;
            string name = null;
            string password = null;

            number = "爱你";
            name = "不变";
            password = "一万年";

            stringinsertSQL = "INSERT INTO TBLSTUDENTS (NUMBER,NAME,PASSWORD) VALUES (' "+ number + " ',' " + name + " ',' " + password + " ');
            mycmd = new OleDbCommand(insertSQL, myconnection);
            //打开链接
            mycmd.Connection.Open();
            try
            {
                mycmd .ExecuteNonQuery();
                //执行查询
            }
            catch(Exception e1)
            {
MessageBox .Show(e1.ToString(),"添加发生错误，请检查参数是否合法");
                mycmd .Connection.Close();
                return;
            }
            mycmd .Connection.Close();

TKS，你改成这样我知道是可以的，我就是想知道我的那个错在哪里，唉

能把源码发给我吗？ ausharp@126.com

mycmd.Parameters.Add("@NUMBER", OleDbType.VarChar).Value = "爱你";或
mycmd.Parameters.Add("@NUMBER", OleDbType.VarChar).value = "爱你";
这样试试看行不