insert-vc执行插入语句不成功是为什么？

sql_update.Format(_T("insert into order_info (patient_id,order_no,order_group_no,p_name,charge_date,state,cancel_flag,start_time,end_time,win_no,order_date,recv_date,his_disp_flag) value （\"%s\",\"%s\",\"%s\",\"%s\",NOW(),6,0,NOW(),NOW(),10,NOW(),NOW(),0)"), patient_id, order_no, order_group_no,p_name);
char* a=sql_update.GetBuffer();
//mysql_query(&g_mysql,"set name 'gbk'");
if(mysql_query(&g_mysql, a) != 0)
{
MessageBox("插入order_info表出错！");
}