主表关联字表，主表自增长，同时插入

方法1：      
  public static bool AdjustLeave(OaLeaveInfo oaLeaveInfo, DataTable dtDetail,decimal dl_OlderYiXiuNianJia,
            string str_userID, string str_plantID, decimal dlDours)
        {
            ArrayList al = new ArrayList();

            //备份原始记录
            string strSql = "insert into oa_leave_origin(origin_sid, user_id, dept_sid, pst_sid, date_from," +
                            "date_to, lc_sid, Reason, com_hour, al_day, rfs_sid, rf_sid, curr_node_no, curr_approver," +
                            "leave_total_days,leave_total_real_days,leave_total_hours," +
                            "create_person, create_date, update_person, update_date,adjust_person,adjust_date)" +
                            "select sid, user_id, dept_sid, pst_sid, date_from," +
                            "date_to, lc_sid, Reason, com_hour, al_day, rfs_sid, rf_sid, curr_node_no, curr_approver," +
                            "leave_total_days,leave_total_real_days,leave_total_hours," +
                            "create_person, create_date, update_person,update_date,'" + BllPubSafe.ConvertString(oaLeaveInfo.UpdatePerson) + "' adjust_person," +
                            "getdate() as adjust_date from oa_leave (nolock) where sid='" + oaLeaveInfo.Sid + "'";
            al.Add(strSql);

            strSql = "insert into oa_leave_detail_origin(p_sid,origin_sid,origin_p_sid,no,leave_category,tick,leave_days," +
                            "date_from,date_to,hours) " +
                            "select (select SCOPE_IDENTITY()),sid,p_sid,no,leave_category,tick,leave_days,date_from,date_to,hours " +
                            "from oa_leave_detail " +
                            "where p_sid = '" + oaLeaveInfo.Sid + "'";
            al.Add(strSql);

            //原始表
            StringBuilder sbSql = new StringBuilder();
            sbSql.Append("update oa_leave set date_from = '" + oaLeaveInfo.DateFrom + "',");
            sbSql.Append("date_to = '" + oaLeaveInfo.DateTo + "',");
            sbSql.Append("reason = '" + oaLeaveInfo.Reason + "',");
            //sbSql.Append("lc_sid = '" + BllPubSafe.ConvertString(oaLeaveInfo.LcSid) + "',");
            //sbSql.Append("com_hour = '" + oaLeaveInfo.ComHour + "',");
            //sbSql.Append("al_day = '" + oaLeaveInfo.AlDay + "'");
            sbSql.Append("leave_total_days = '" + oaLeaveInfo.leaveTotalDays + "',");
            sbSql.Append("leave_total_real_days = '" + oaLeaveInfo.leaveTotalrealDays + "',");
            sbSql.Append("leave_total_hours = '" + oaLeaveInfo.leaveTotalHours + "'");
            sbSql.Append(" where sid = '" + oaLeaveInfo.Sid + "'");

            al.Add(sbSql.ToString());

            //从表
            if (dtDetail.Rows.Count > 0)
            {
                sbSql = new StringBuilder();
                sbSql.Append("delete from oa_leave_detail where p_sid='" + oaLeaveInfo.Sid + "'")
                     .Append("delete from oa_compensative_detail where leave_sid='" + oaLeaveInfo.Sid + "'");
                al.Add(sbSql.ToString());
            }
             DbHelperSQL.ExecuteSqlTran(al);

             DataTable dtTemp = BLL.HR.BLL_HRCommon.getcommtable("select * from fn_oa_leave_left_timeAddModifyTep('" + str_plantID + "','" + BllPubSafe.ConvertString(str_userID) + "')");
            using (SqlConnection conn = new SqlConnection(DbHelperSQL.ConnectionString))
            {
                conn.Open();
                SqlCommand cmd = new SqlCommand();
                cmd.Connection = conn;
                SqlTransaction tx = conn.BeginTransaction();
                cmd.Transaction = tx;
                try
                {
                    //从表
                    for (int i = 0; i < dtDetail.Rows.Count; i++)
                    {
                        sbSql = new StringBuilder();
                        if (dl_OlderYiXiuNianJia.ToString().Trim().Length > 0)
                        {
                            //dlhourday
                            if (dtDetail.Rows[i]["no"].ToString() == "C")
                            {
                                sbSql.Append(" update KQ_EmpYearVac set Vac_Been=(Vac_Been+" +
                                    Convert.ToDecimal(dtDetail.Rows[i]["leave_days"].ToString()) +
                                   " -" + dl_OlderYiXiuNianJia
                                    + ")  where Plant_Id='" + str_plantID + "' and Vac_Year='" + DateTime.Now.Year +
                                    "' and Employee_Id='" + str_userID + "' ");
                                cmd.CommandText = sbSql.ToString();
                                cmd.ExecuteNonQuery();
                            }
                            else if (i == 0)
                            {
                                sbSql.Append(" update KQ_EmpYearVac set Vac_Been=(Vac_Been+" +
                                        0 +
                                        " -" + dl_OlderYiXiuNianJia
                                         + ")  where Plant_Id='" + str_plantID + "' and Vac_Year='" + DateTime.Now.Year +
                                         "' and Employee_Id='" + str_userID + "' ");
                                cmd.CommandText = sbSql.ToString();
                                cmd.ExecuteNonQuery();
                            }

                        }
                        if (dtDetail.Rows[i]["no"].ToString() == "D")
                        {
                            sbSql.Append(" insert oa_leave_detail(no,leave_category,tick,leave_days,date_from,date_to,p_sid,hours)values(");
                            sbSql.Append("'" + dtDetail.Rows[i]["no"].ToString() + "',");
                            sbSql.Append("'" + dtDetail.Rows[i]["leave_category"].ToString() + "',");
                            sbSql.Append("'" + Convert.ToInt32(dtDetail.Rows[i]["tick"]) + "',");
                            sbSql.Append("'" + Convert.ToDecimal(dtDetail.Rows[i]["leave_days"].ToString()) + "',");
                            sbSql.Append("'" + dtDetail.Rows[i]["date_from"].ToString() + "',");
                            sbSql.Append("'" + dtDetail.Rows[i]["date_to"].ToString() + "',");
                            sbSql.Append("'" + oaLeaveInfo.Sid + "',");
                            sbSql.Append("'" + Convert.ToDecimal(dtDetail.Rows[i]["hours"].ToString()) + "')");
                            //主表
                            cmd.CommandText = sbSql.ToString();
                            cmd.ExecuteNonQuery();
                            //获取ID
                            cmd.CommandText = "select SCOPE_IDENTITY()";
                            string strMID = cmd.ExecuteScalar().ToString();
                            decimal dlTemp = 0;
                            decimal dlTemp1 = 0;
                          
                            dlTemp1 = Convert.ToDecimal(dtDetail.Rows[i]["leave_days"].ToString()) * dlDours +
                            Convert.ToDecimal(dtDetail.Rows[i]["hours"].ToString());

                            for (int j = 0; j < dtTemp.Rows.Count; j++)
                            {
                                sbSql = new StringBuilder();
                                if (BLL.HR.BLL_HRCommon.returndecimal(dtTemp.Rows[j]["lefttime"].ToString()) - dlTemp1 > 0)
                                {
                                    sbSql.Append("insert oa_compensative_detail(overtime_sid,cps_sid,cps_hours,leave_sid)values('" +
                                    dtTemp.Rows[j]["sid"].ToString() + "','" + strMID + "','" +
                                   dlTemp1 + "','" + oaLeaveInfo.Sid + "')");
                                    cmd.CommandText = sbSql.ToString();
                                    cmd.ExecuteNonQuery();
                                    break;
                                }
                                else
                                {
                                    dlTemp = BLL.HR.BLL_HRCommon.returndecimal(dtTemp.Rows[j]["lefttime"].ToString());

                                    if (dlTemp1 - dlTemp > 0)
                                    {
                                        sbSql.Append("insert oa_compensative_detail(overtime_sid,cps_sid,cps_hours,leave_sid)values('" +
                                        dtTemp.Rows[j]["sid"].ToString() + "','" + strMID + "','" +
                                        dlTemp + "','" + oaLeaveInfo.Sid + "')");
                                        dlTemp1 = dlTemp1 - dlTemp;
                                        cmd.CommandText = sbSql.ToString();
                                        cmd.ExecuteNonQuery();                                       
                                    }
                                    else
                                    {
                                        sbSql.Append("insert oa_compensative_detail(overtime_sid,cps_sid,cps_hours,leave_sid)values('" +
                                        dtTemp.Rows[j]["sid"].ToString() + "','" + strMID + "','" +
                                        dlTemp1 + "','" + oaLeaveInfo.Sid + "')");
                                        cmd.CommandText = sbSql.ToString();
                                        cmd.ExecuteNonQuery();
                                        break;
                                    }
                                }
                            }
                        }
                        else
                        {
                            sbSql = new StringBuilder();
                            sbSql.Append(" insert oa_leave_detail(no,leave_category,tick,leave_days,date_from,date_to,p_sid,hours)values(");
                            sbSql.Append("'" + dtDetail.Rows[i]["no"].ToString() + "',");
                            sbSql.Append("'" + dtDetail.Rows[i]["leave_category"].ToString() + "',");
                            sbSql.Append("'" + Convert.ToInt32(dtDetail.Rows[i]["tick"]) + "',");
                            sbSql.Append("'" + Convert.ToDecimal(dtDetail.Rows[i]["leave_days"].ToString()) + "',");
                            sbSql.Append("'" + dtDetail.Rows[i]["date_from"].ToString() + "',");
                            sbSql.Append("'" + dtDetail.Rows[i]["date_to"].ToString() + "',");
                            sbSql.Append("'" + oaLeaveInfo.Sid + "',");
                            sbSql.Append("'" + Convert.ToDecimal(dtDetail.Rows[i]["hours"].ToString()) + "')");
                            cmd.CommandText = sbSql.ToString();
                            cmd.ExecuteNonQuery();
                        }
                    }
                    tx.Commit();
                }
                catch (System.Data.SqlClient.SqlException E)
                {
                    tx.Rollback();
                    throw new Exception(E.Message);
                }
            }
           
            return true;

        }

方法2：
   可通过
create trigger trUser_insert on tbUser for insert as

select @@identity

go 
获取最后一次出现的标识

方法3：
同时也可以
set nocount on;
insert into tbUser (a,b) values(“a”,”b”);
select @@identity; 
获取ID