按Points和CompetitionName降序对每个Sections进行分组

Question

C1 - Competition1, C2 - Competition2, C3 - Competition3. C1Points - Compeletion1Points

This table represents a points table in which different categories of students participating in different types of competitions.

Columns C1, C2, C3 are name of the competitions, if the value is '1' that student is participating that competition. if '0' he is not participating.

S1 to S15                     : Student Names
C1 ,C2,C3                     : Competition Names
Section                       : Indicates category of that particular student
C1points, C2points, C3points  : Points received by the particular student in that particular competition

Here I would like to group each Sections by Points and Competition Name descending order.

Please Note : C1 Need to change Competition1, C2 - Competition2, C3 - Competition3

please refer : http://www.sqlfiddle.com/#!2/20920/1

My final output looks like

Answer 1

Only for Section 1. You can similarly implement logic for Section 2 and Section 3

select *
from
(
select s1.ID,
s1.Name,
'Competition 1' as Competition,
s1.C1Points as Points
from students s1
where SECTION='Section1'
and ifnull(s1.C1,'')<>''
and s1.C1Points<>0
union
select s2.ID,
s2.Name,
'Competition 2' as Competition,
s2.C2Points as Points
from students s2
where s2.SECTION='Section1'
and ifnull(s2.C2,'')<>''
and s2.C2Points<>0
union
select s3.ID,
s3.Name,
'Competition 3' as Competition,
s3.C3Points as Points
from students s3
where s3.SECTION='Section1'
and ifnull(s3.C2,'')<>''
and s3.C3Points<>0
)t
order by t.points desc,t.Competition desc

SQl Fiddle

Answer 2

You can try with following query for all sections combined:

select ID,name,comp_desc,points 
from (
select section,ID,name, 'Competion1' as comp_desc, C1Points as points
from students
union
select section,ID,name, 'Competion2' as comp_desc, C2Points as points 
from students
union
select section,ID,name, 'Competion3' as comp_desc, C3Points as points 
from students
) t
where points <> 0
group by section, name,comp_desc, points
order by  section, points desc, comp_desc desc;

Although i still think the output showed by you needs little more description. for example as identified by Luv why in section 1, for S13 competition2 is coming before 3. Again for section 2, why S14 is coming before S10 for competition 2.

However, I think you can now modify the above query to suit your needs.

Answer 3

select * from
(select 
  section
  ,id
  ,name
  ,"Competition 1" as Competition
  ,C1Points as Points
from 
  students
where
  C1 = 1
union
select
  section
  ,id
  ,name
  ,"Competition 2" as Competition
  ,C2Points as Points
from 
  students
where
  C2 = 1
union
select
  section
  ,id
  ,name
  ,"Competition 2" as Competition
  ,C2Points as Points
from 
  students
where
  C3 = 1
 ) agg
order by
section, points desc