WITH table AS及其他

WITH table AS 临时表使用方法

SET ANSI_NULLS ONGOSET QUOTED_IDENTIFIER ONGOIF EXISTS (SELECT * FROM sys.views WHERE object_id = OBJECT_ID(N'[dbo].[v_Order_Production_Scheduling]'))BEGIN    DROP VIEW [dbo].v_Order_Production_Scheduling;ENDGO-- =============================================-- =============================================CREATE view [dbo].v_Order_Production_Scheduling AS WITH tb AS (SELECT VBELN, POSNR, ETENR, WMENG, EDATU, VRKME, WERKS, o.new_number as o_number, od.new_number as od_number, sd.new_number as sd_shippingline, sd.new_schedulingdetailsId as sd_schedulingdetailsId            FROM PRODUCTION_SCHEDULING as ps             LEFT JOIN dbo.new_order as o             ON ps.VBELN = o.new_sapnumber             LEFT JOIN dbo.new_orderdetails as od             ON ps.POSNR = od.new_sapnumber             AND o.new_orderId = od.new_orderId             LEFT JOIN dbo.new_schedulingdetails as sd             ON ps.ETENR = sd.new_number             AND od.new_orderdetailsId = sd.new_orderdetailsid             )SELECT VBELN, POSNR, ETENR, WMENG, EDATU, VRKME, WERKS, o_number, od_number, sd_shippingline, sd_schedulingdetailsId, '更新' AS describe FROM tb WHERE tb.sd_schedulingdetailsId IS NOT NULL UNION ALLSELECT VBELN, POSNR, ETENR, WMENG, EDATU, VRKME, WERKS, o_number, od_number, sd_shippingline, sd_schedulingdetailsId, '创建' AS describe FROM tb WHERE tb.o_number IS NOT NULL AND tb.od_number IS NOT NULL AND ETENR IS NOT NULLAND tb.sd_schedulingdetailsId IS NULL

两个对象都没有判空处理
如果前一对象为NULL，结果怎么样？
如果后一对象为NULL，结果怎么样？

schedulingdetails.Attributes["new_planline"].ToString() != viewlist.Tables[0].Rows[i]["ETENR"].ToString()

试验如下

string a = null;string b = null;string c = "c";string d = "d";Console.WriteLine(a != c);Console.WriteLine(c != a);Console.WriteLine(a != b);Console.WriteLine(c != d);

选项集赋值

schedulingdetails.Attributes["new_factory"] = new OptionSetValue(int.Parse(viewlist.Tables[0].Rows[i]["WERKS"].ToString()));