I am trying to write a query that selects the Top record in each Group of Data.
eg Below
Division
Team
Points
1
Liverpool
90
1
Manchester
88
2
Leeds
94
2
Arsenal
77
3
Bolton
66
3
Spurs
72
3
Derby
33
I want my query to return the team with highest number of points in each division:
Division
Team
Points
1
Liverpool
90
2
Leeds
94
3
Spurs
72
I thought this should be easy.
Any ideas?
Thanks
In MS Access, you can use:
select t.*
from t
where t.points = (select max(t2.points)
from t t2
where t2.division = t.division
);
If there are ties, then this returns all matching teams. If you want only one team even when there are ties:
select t.*
from t
where t.team = (select t2.team
from t t2
where t2.division = t.division
order by t2.points desc, t2.team
);
Related
I have 2 simple tables as follows:-
Student
---------------------------------------------
student_id student_name student_class
107 paul A Level-I
108 susan Diploma
109 jack O Level-II
---------------------------------------------
Student_Positions
--------------------------------------------------
position_id student_id position date
1 107 1 1-1-2020
2 107 1 1-1-2021
3 109 2 1-1-2021
4 109 1 1-6-2019
I want a left outer join on these tables for the latest position of every student as fol:-
student_id student_name position date
107 paul 1 1-1-2021
108 susan
109 jack 2 1-1-2021
I have made multiple tries with different positions of max(date) and group by but in vain.
Please help with correct query
The canonical SQL solution uses a window function such as row_number():
select s.*, sp.position, sp.date
from students s left join
(select sp.*,
row_number() over (partition by student_id order by date desc) as seqnum
from student_positions sp
) sp
on sp.student_id = s.student_id and sp.seqnum = 1;
By using SQL query, find out the Top 5 highest total Transaction Value, which Industry are they? and the number of stores in that industry?
My SQL data looks like this:
Store Name
Industry
Transaction Value
Ace
A
196
Ace
A
193
Area
A
168
Apple
A
165
Boy
B
145
Boy
B
143
Bull
B
136
Bread
B
131
Cat
C
116
Cat
C
106
Cake
C
104
Candy
C
102
Dog
D
101
Dog
D
92
Door
D
80
Daddy
D
75
Egg
E
70
Egg
E
67
Earl
E
66
Eagle
E
61
This is just for your reference, Top 5 highest Transaction Value are:
No.
Store Name
Industry
Total Transaction Value
1
Ace
A
389
2
Boy
B
288
3
Cat
C
222
4
Dog
D
193
5
Area
A
168
SQL Query Results should look something like this:
Industry
No. of Stores
A
2
B
1
C
1
D
1
E
0
select a.industry, sum(case when b.name is null then 0 else 1 end) as no
from
(select distinct industry from transactions ) a
left join
(select name, industry
from transactions
group by name, industry
order by sum(transaction_vaule) desc limit 5) b
on a.industry = b.industry
group by a.industry
order by a.industry
I think I have a solution for you. Please check my code I have used Common Table Expression ,CASE,SUM and group by =>
WITH CTE AS
(
SELECT industry, SUM(TransactionValue) AS Transaction_Value,
COUNT(StoreName) AS StoreCount FROM MYTable
GROUP BY StoreName,industry
ORDER BY SUM(TransactionValue) DESC
Limit 5
)
SELECT T1.industry,
SUM((CASE WHEN c.industry IS NULL THEN 0
ELSE 1 END)) as CT
FROM
(SELECT DISTINCT Industry FROM MYTable) AS T1
LEFT JOIN CTE as c ON T1.industry=c.industry
GROUP BY T1.industry
Note: Subquery is not best practice, but in your case, I think there will be no performance issue. Also, please check the code because, I do not have Snowflake SQL database installed, so there might be some syntactical error can be evident
.
To get a deterministic result, you must be aware of ties. Let's say the top 9 results are
Cat/A/600, Dog/A/500, Cat/B/500, Dog/B/400, Cat/C/300, Dog/C/300, Cat/D/300, Dog/D/200, Cat/E/100
Which is the top fifth? Cat/C/300 or Dog/C/300 or Cat/D/300? Or none of them? If we pick a row arbitrarily (by LIMIT 5 or FETCH FIRST 5 ROWS ONLY) we prefer one industry over another.
In standard SQL we have the clause FETCH FIRST 5 ROWS WITH TIES, but snowflake doesn't feature this, unfortunately. It does however feature DENSE_RANK. It ranks my sample rows thus:
#1: Cat/A/600
#2: Dog/A/500
#2: Cat/B/500
#3: Dog/B/400
#4: Cat/C/300
#4: Dog/C/300
#4: Cat/D/300
#5: Dog/D/200
#6: Cat/E/100
because the five top values are 600, 500, 400, 300, and 200.
The query:
select industry, count(case when rnk <= 5 then 1 end) as stores
from
(
select industry, dense_rank() over (order by sum(transaction_value) desc) as rnk
from mytable
group by store_name, industry
) ranked
group by industry
order by industry;
If you only want to show top industries:
select industry, count(*) as stores
from
(
select industry, dense_rank() over (order by sum(transaction_value) desc) as rnk
from mytable
group by store_name, industry
) ranked
where rnk <= 5
group by industry
order by industry;
I sorted my data to something like this and now I want to get top 3 max person_occurence by every company but I couldn't figure out how to do it.
person_occurence company person_id
67 company_1 110
66 company_2 176
64 company_3 100
64 company_3 196
63 company_4 127
62 company_1 150
61 company_5 120
60 company_3 140
59 company_5 154
59 company_5 162
59 company_4 194
58 company_4 109
58 company_3 128
58 company_1 156
I used this query to get max of every company but can't get top 3 max person_occurence
SELECT max(agent_occurence), company FROM table GROUP BY company;
Use window functions:
select t.*
from (select t.*,
row_number() over (partition by company order by person_occurrence desc) as seqnum
from t
) t
where seqnum <= 3;
Now, this assumes that you want the top 3 regardless of ties -- that is, if 4 are tied with the same highest value, this returns three of them. Ties make things more difficult. You may want dense_rank() or rank() instead.
You can use correlated subquery :
SELECT t1.*
FROM table t1
WHERE t1.person_occurencee = (SELECT max(t2.person_occurence) FROM table t2 WHERE t1.company = t2.company);
If your DBMS supports analytical function then you can also do :
select t.*
from (select t.*,
rank() over (partition by company order by person_occurrence desc) as seq
from t
) t
where seq <= 3;
I'm using below for a tournament system. The table contains registrered lengths for all teams. The result will be a scoreboard, summing up all teams length in a totalScore.
I'm trying to get the RANK() function into my SQL but I'm stuck right now. I want to get the current teams rank score out from my DB. Anyone got any ideas? I'm using MariaDB.
select team, sum(length) as totalScore
from
(SELECT t.*,
#num_in_group:=case when #team!=team then #num_in_group:=0 else #num_in_group:=#num_in_group+1 end as num_in_group,
#team:=team as t
FROM reg_catches t, (select #team:=-1, #num_in_group:=0) init
ORDER BY team asc, length desc) sub
WHERE sub.num_in_group<=4
GROUP BY team
ORDER BY totalScore DESC;
Table
team length
-----------
26 70
25 70
25 95
25 98
25 100
25 100
25 100
25 122
Current output
team totalScore
-- --
25 520
26 70
Wanted output
rank team totalScore
-- -- --
1 25 520
2 26 70
SET #row = 0;
SELECT #row:=#row + 1 rank, a.team, a.total_score
FROM(SELECT team, sum(r.length) as total_score FROM reg_catches r GROUP BY
r.team) a;
Try the above
Got this far now with above help from Dickson, problem now is that it seems that the rank is based on team ID instead of totalScore :O
SET #row = 0;
SELECT #row:=#row + 1 rank, team, sum(length) as totalScore
from
(SELECT t.*,
#num_in_group:=case when #team!=team then #num_in_group:=0 else #num_in_group:=#num_in_group+1 end as num_in_group,
#team:=team as t
FROM reg_catches t, (select #team:=-1, #num_in_group:=0) init
ORDER BY team asc, length desc) sub
WHERE sub.num_in_group<=4 and competition = "#COMPID" and disqualified = 0
GROUP BY team
ORDER BY totalScore DESC
Current output
rank team totalScore
1 28381 479
58 28468 439
20 28412 436
25 28419 432
14 28404 427
5 28388 421
Wanted would be
rank team totalScore
1 28381 479
2 28468 439
3 28412 436
4 28419 432
5 28404 427
6 28388 421
SQL Fiddle: http://sqlfiddle.com/#!9/107d98/2/1
This question is probably answered before but i cant find how to get the latest records of the months.
The problem is that I have a table with sometimes 2 row for the same month. I cant use the aggregate function(I guess) cause in the 2 rows, i have different data where i need to get the latest.
Example:
name Date nuA nuB nuC nuD
test1 05/06/2013 356 654 3957 7033
test1 05/26/2013 113 237 399 853
test3 06/06/2013 145 247 68 218
test4 06/22/2013 37 37 6 25
test4 06/27/2013 50 76 20 84
test4 05/15/2013 34 43 34 54
I need to get a result like:
test1 05/26/2013 113 237 399 853
test3 06/06/2013 145 247 68 218
test4 05/15/2013 34 43 34 54
test4 06/27/2013 50 76 20 84
** in my example the data is in order but in my real table the data is not in order.
For now i have something like:
SELECT Name, max(DATE) , nuA,nuB,nuC,nuD
FROM tableA INNER JOIN
Group By Name, nuA,nuB,nuC,nuD
But it didn't work as i want.
Thanks in advance
Edit1:
It seems that i wasn't clear with my question...
So i add some data in my example to show you how i need to do it.
Thanks guys
Use SQL Server ranking functions.
select name, Date, nuA, nuB, nuC, nuD from
(Select *, row_number() over (partition by name, datepart(year, Date),
datepart(month, Date) order by Date desc) as ranker from Table
) Z
where ranker = 1
Try this
SELECT t1.* FROM Table1 t1
INNER JOIN
(
SELECT [name],MAX([date]) as [date] FROM Table1
GROUP BY [name],YEAR([date]),MONTH([date])
) t2
ON t1.[date]=t2.[date] and t1.[name]=t2.[name]
ORDER BY t1.[name]
Can you not just do an order
select * from tablename where Date = (select max(Date) from tablename)
followed by only pulling the first 3?