请问一下 为什么编入下面的语句无法在数据库中增加数据？

Question

数据库数据

Answer 1

  string connectionString = "server=(local);User ID=sa;Password=123;database=school;Connection Reset=FALSE";
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
               
                connection.Open();
                using (SqlCommand cmd = new SqlCommand("Insert into dbo.class(id,name,pwd) values('" + s1+ "','" + s1 + "','" + s1 + "')", connection))
                {
                    try
                    {  
                        cmd.ExecuteNonQuery();
                        Response.Write("<script>alert(\"已注册\")</Script>");
                    }
                    catch (Exception m)
                    { 
                        Response.Write("错误"+m); 
                    }
                    finally
                    {
                        cmd.Dispose();
                        connection.Close();
                    }
                }
            }