在论坛中出现的比较难的sql问题:3
最近,在论坛中,遇到了不少比较难的sql问题,虽然自己都能解决,但发现过几天后,就记不起来了,也忘记解决的方法了。
所以,觉得有必要记录下来,这样以后再次碰到这类问题,也能从中获取解答的思路。另外,考虑到前2篇太长,看起来不太方便,所以拆分为第3篇
http://bbs.csdn.net/topics/390619048
情境描述:根据表A里的物料去比对表B,然后表A根据A1括号里两个尺寸浪费最少来将A1替换成最省的物料。
表A用量需求表:Table A
A0(自增长ID) A1(物料编号)
-------------------------------
0 ls001-(900*110)
1 ls002-(200*300)
....
表B库存物料表: B1没有重复,可以当作ID来使用 Table B:
B1(库存物料) B2(规格1) B3(规格2)
----------------------------------------------
ls001-(700*200) 700 200
ls001-(910*140) 910 140
ls001-(920*120) 920 120
... ... ...
ls002-(100*200) 100 200
ls002-(200*350) 200 350
ls002-(220*320) 220 320
...
原理是:ls001取(920*120)的话浪费分别是左边920-900=20,右边120-110=10,总共浪费是30, 是ls001库存规格(700*200),(910*140),(920*120)里浪费最少的,ls002同理。
最后A1字段被替换后的效果如下:
A0(自增长ID) A1(物料编号)
-------------------------------
0 ls001-(920*120)
1 ls002-(220*320)
...
各位有什么好的方案或者算法可分享来学习借鉴一下 ^_^
我的解法:
drop table adrop table bcreate table a (a0 int,a1 varchar(100),a2 int,a3 int)insert into aSELECT 0,'ls001-(900*110)',900,110 UNION ALLSELECT 1,'ls002-(200*300)',200,300create table b (B1 varchar(100),B2 int,B3 int)insert into b SELECT 'ls001-(700*200)',700,200 UNION ALLSELECT 'ls001-(910*140)',910,140 UNION ALLSELECT 'ls001-(920*120)',920,120 UNION ALLSELECT 'ls002-(100*200)',100,200 UNION ALLSELECT 'ls002-(200*350)',200,350 UNION ALLSELECT 'ls002-(220*320)',220,320;with tas(select a0,a1, substring(a1,1,charindex('-',a1)-1) as b1, a2,a3 --substring(a1,charindex('(',a1)+1, charindex('*',a1)-charindex('(',a1)-1) as b2, --substring(a1,charindex('*',a1)+1, charindex(')',a1)-charindex('*',a1)-1) as b3 from a),ttas(select t.a0, t.a1, b.b1, row_number() over(partition by t.a1 order by abs(t.a2-b.b2) + abs(t.a3 - b.b3)) as rownumfrom binner join t on b.b1 like t.b1 + '%')select a0,b1 as a1from tt where rownum = 1/*a0a10ls001-(920*120)1ls002-(220*320)*/
2、sql中怎么判断某个字段的值是否连续?
http://bbs.csdn.net/topics/390615670
比如:A表的字段AID的值为:1、2、4、5、7、8、10
怎么用sql查询出2、5、8的结果呢?
要查的结果就是查询这组数据从哪里开始不连续的。
我的解法:
create table A(AID int) insert into A(AID) select 1 union all select 2 union all select 4 union all select 5 union all select 7 union all select 8 union all select 10select aidfrom(select a.aid, (select min(aid) from a aa where aa.aid > a.aid) min_aidfrom A )awhere aid +1 < min_aid/*aid258*/
3、关于日期条件出现的奇怪问题。
http://bbs.csdn.net/topics/390498925
select top 1 ekeyid,ProbeMaterial,Result,LabTestDate from PatientLabTestResults
where ProbeMaterial='Ca'
and LabTestDate between convert(datetime,2013/1/1) and
convert(datetime,'2013/6/24') order by LabTestDate desc
这样查的出结果,变成
select top 1 ekeyid,ProbeMaterial,Result,LabTestDate from PatientLabTestResults
where ProbeMaterial='Ca'
and LabTestDate between convert(datetime,2013/1/1) and
convert(datetime,2013/6/24) order by LabTestDate desc
这样后就查不出结果了,其实只是去除了2013/6/24的'号而已,这个大家能理解是什么问题吗?
select top 200 id, ClassId,Name,Price,BoxContain,BoxLength,BoxWidth,BoxHeight,CName,EName,CPack,PhotoFolder,EPack,0.46*(round(((convert(decimal(10,2),BoxLength)*convert(decimal(10,2),BoxWidth) * convert(decimal(10,2),BoxHeight))/1000000),3))*35.32/BoxContain+Price/6*1.08 from ProductData where ClassId=101 and BoxContain >0 and BoxContain is not null and round(((convert(decimal(10,2),BoxLength)*convert(decimal(10,2),BoxWidth) * convert(decimal(10,2),BoxHeight))/1000000),3) >=0 And round(((convert(decimal(10,2),BoxLength)*convert(decimal(10,2),BoxWidth) * convert(decimal(10,2),BoxHeight))/1000000),3) <= 10000 and (0.46*(round(((convert(decimal(10,2),BoxLength)*convert(decimal(10,2),BoxWidth) * convert(decimal(10,2),BoxHeight))/1000000),3))*35.32/BoxContain+Price/6*1.08) >=10 and (0.46*(round(((convert(decimal(10,2),BoxLength)*convert(decimal(10,2),BoxWidth) * convert(decimal(10,2),BoxHeight))/1000000),3))*35.32/BoxContain+Price/6*1.08) <=1000 and EPack='Window Box' order by id asc
declare @page_size int;declare @page_num int;--比如:每页10条记录set @page_size = 10;--比如:先取第1页set @page_num = 1;select *from(select *, row_number() over(order by @@servername) as rownum, --这里按照@@servername来排序, --你可以根据需要按照id,sid,sname等字段来排序 (row_number() over(order by @@servername) - 1) / @page_size as pagenumfrom sys.objects)twhere pagenum = @page_num - 1