SQL groupby multiple columns - sql

Question

Tablename: EntryTable
ID CharityName Title VoteCount
1 save the childrens save them 1
2 save the childrens saving childrens 3
3 cancer research support them 10
Tablename: ContestantTable
ID FirstName LastName EntryId
1 Neville Vyland 1
2 Abhishek Shukla 1
3 Raghu Nandan 2
Desired output
CharityName FullName
save the childrens Neville Vyland
Abhishek Shukla
cancer research Raghu Nandan
I tried
select LOWER(ET.CharityName) AS CharityName,COUNT(CT.FirstName) AS Total_No_Of_Contestant
from EntryTable ET
join ContestantTable CT
on ET.ID = CT.ID
group by LOWER(ET.CharityName)
Please advice.

Answer 1

Please have a look at this sqlfiddle.
Have a try with this query:
SELECT
e.CharityName,
c.FirstName,
c.LastName,
sq.my_count
FROM
EntryTable e
INNER JOIN ContestantTable c ON e.ID = c.EntryId
INNER JOIN (
SELECT EntryId, COUNT(*) AS my_count FROM ContestantTable GROUP BY EntryId
) sq ON e.ID = sq.EntryId
I assumed you actually wanted to join with ContestantTable's EntryId column. It made more sense to me. Either way (joining my way or yours) your sample data is faulty.
Apart from that, you didn't want repeating CharityNames. That's not the job of SQL. The database is just there to store and retrieve the data. Not to format it nicely. You want to work with the data on application layer anyways. Removing repeating data doesn't make this job easier, it makes it worse.

Answer 2

Most people do not realize that T-SQL has some cool ranking functions that can be used with grouping. Many things like reports can be done in T-SQL.
The first part of the code below creates two local temporary tables and loads them with data for testing.
The second part of the code creates the report. I use two common table expressions (CTE). I could have used two more local temporary tables or table variables. It really does not matter with this toy example.
The cte_RankData has two columns RowNum and RankNum. If RowNum = RankNum, we are on the first instance of charity. Print out the charity name and the total number of votes. Otherwise, print out blanks.
The name of the contestant and votes for that contestant are show on the detail lines. This is a typical report with sub totals show at the top.
I think this matches the report output that you wanted. I ordered the contestants by most votes descending.
Sincerely
John Miner
www.craftydba.com
--
-- Create the tables
--
-- Remove the tables
drop table #tbl_Entry;
drop table #tbl_Contestants;
-- The entries table
Create table #tbl_Entry
(
ID int,
CharityName varchar(25),
Title varchar(25),
VoteCount int
);
-- Add data
Insert Into #tbl_Entry values
(1, 'save the childrens', 'save them', 1),
(2, 'save the childrens', 'saving childrens', 3),
(3, 'cancer research', 'support them', 10)
-- The contestants table
Create table #tbl_Contestants
(
ID int,
FirstName varchar(25),
LastName varchar(25),
EntryId int
);
-- Add data
Insert Into #tbl_Contestants values
(1, 'Neville', 'Vyland', 1),
(2, 'Abhishek', 'Shukla', 1),
(3, 'Raghu', 'Nandan', 2);
--
-- Create the report
--
;
with cte_RankData
as
(
select
ROW_NUMBER() OVER (ORDER BY E.CharityName ASC, VoteCount Desc) as RowNum,
RANK() OVER (ORDER BY E.CharityName ASC) AS RankNum,
E.CharityName as CharityName,
C.FirstName + ' ' + C.LastName as FullName,
E.VoteCount
from #tbl_Entry E inner join #tbl_Contestants C on E.ID = C.ID
),
cte_SumData
as
(
select
E.CharityName,
sum(E.VoteCount) as TotalCount
from #tbl_Entry E
group by E.CharityName
)
select
case when RowNum = RankNum then
R.CharityName
else
''
end as rpt_CharityName,
case when RowNum = RankNum then
str(S.TotalCount, 5, 0)
else
''
end as rpt_TotalVotes,
FullName as rpt_ContestantName,
VoteCount as rpt_Votes4Contestant
from cte_RankData R join cte_SumData S
on R.CharityName = S.CharityName