技术面试-oracle分析函数

createtableearnings--打工赚钱表(earnmonthvarchar2(6),--打工月份areavarchar2(20),--打工地区snovarchar2(10),--打工者编号snamevarchar2(20),--打工者timesint,--本月打工次数enumber(10,2),--每次赚enumber(10,2)--当月总收入insertintoearningsvalues('200912','北平','511601','',11,30,11*30);insertintoearningsvalues('200912','北平','511602','大凯',8,25,8*25);insertintoearningsvalues('200912','北平','511603','',30,6.25,30*6.25);insertintoearningsvalues('200912','北平','511604','大亮',16,8.25,16*8.25);insertintoearningsvalues('200912','北平','511605','贱敬',30,11,30*11);insertintoearningsvalues('200912','金陵','511301','',15,12.25,15*12.25);insertintoearningsvalues('200912','金陵','511302','',27,16.67,27*16.67);insertintoearningsvalues('200912','金陵','511303','小妮',7,33.33,7*33.33);insertintoearningsvalues('200912','金陵','511304','小俐',0,18,0);insertintoearningsvalues('200912','金陵','511305','雪儿insertintoearningsvalues('201001','北平','511601','',0,30,0);insertintoearningsvalues('201001','北平','511602','大凯',14,25,14*25);insertintoearningsvalues('201001','北平','511603','',19,6.25,19*6.25);insertintoearningsvalues('201001','北平','511604','大亮',7,8.25,7*8.25);insertintoearningsvalues('201001','北平','511605','贱敬',21,11,21*11);insertintoearningsvalues('201001','金陵','511301','',6,12.25,6*12.25);insertintoearningsvalues('201001','金陵','511302','',17,16.67,17*16.67);insertintoearningsvalues('201001','金陵','511303','小妮',27,33.33,27*33.33);insertintoearningsvalues('201001','金陵','511304','小俐',16,18,16*18);insertintoearningsvalues('201001','金陵','511305','雪儿',11,9.88,11*9.88);select*fromsumselectearnmonth,area,sum( fromearningsgroupbyearnmonth,areaorderbyrollupselectearnmonth,area,sum( fromearningsgroupbyrollup(earnmonth,cube按照月份，地区进行收入selectearnmonth,area,sum( fromearningsgroupbycube(earnmonth,area)orderbyearnmonth,areanullslast;groupbyearnmontharea以上三例都是先按照earnmonth分组，在earnmonth内部再按area分组，并在area组内统 e总合groupbygroupgroupbyrollupgroupbyearnmonthgroupbycubeearnmontharea另外那个nullslast是把空值放在最后。(4)grou函在以上例子中，是用rollup和cube函数都会对结果集产生null，这时候可用grou函数来确认 函数用法，带一个参数，参数为字段名，1，Sql代 selectdecode(grou(earnmonth),1,'所有月份',earnmonth)月份,decode(grou(area),1,'全部地区',area)地区, e)总金额fromgroupbycube(earnmonth,area)orderbyearnmonth,areanullslast;rank()overSql代 selectearnmonth月份area地区,sname打工者,e收入rank()over(partitionbyearnmonth,areaorderby edesc)fromearnings;dense_rank()overSql代码 selectarea,sname,edense_rank()over(partitionbyearnmonth,areaorderby edesc)paimingfromearnings;row_number()overSql代码 selectearnmontharea,sname,erow_number()over(partitionbyearnmonth,areaorderby edesc)fromearnings;通过(5)(6)(7)rank,dense_rank,row_number结果集中如果出现两个相同的数据，那么rank会进行跳跃式的，但是dense_rank不会跳跃式的，两个第二接下来还是第三row_number最牛，即使两个数据相同，也不一样sumSql代 selectearnmonth月份area地区,sname打工者, e)over(partitionbyearnmonth,areaorder e)总收入fromSql代 selectdistinctearnmontharea e)over(partitionbyearnmonth,area) e)over(partitionbyearnmonth,area) e)over(partitionbyearnmonth,area) e)over(partitionbyearnmonth,fromlaglead求出每个打工者上个月和下个月有没有赚钱 e大于零即为赚钱Sql代 selectearnmonth本月sname打工者 e,0),0,'没赚','赚了'),1,0)over(partitionbysnameorderbyearnmonth)上月 e,0),0,'没赚','赚了'),1,0)over(partitionbysnameorderbyearnmonth)下月from说明：LagLeadNN（可以是其他字段的数据，比如根据字段甲查询上lag(value_expression[,offset][,default])over([query_partition_clase]order_by_clause)；lead(value_expression[,offset][,default])over([query_partition_clase]order_by_clause)；value_expr