Select max value in subquery in SQL - sql

I have a query like below:
select *
from
(select
centre_name, sum(qty) as number1
from
(select
exchange_from_centre_id as cenid,
count(exchange_from_centre_id) as qty
from
as2.exchange
group by
exchange_from_centre_id
union all
select
exchange_to_centre_id as cenid,
count(exchange_to_centre_id) as qty
from
as2.exchange
group by
exchange_to_centre_id), as2.centre c
where
c.centre_id = cenid
group by
centre_name);
and this is the result: Name of the centre and the number of exchange
Alice Springs Desert Park 1
Werribee Open Range Zoo 6
Kruger National Park 2
Johannesburg Zoo 4
Australia Zoo 2
SanWild Wildlife Sanctuary 5
I like to select the max value from this result (the 2nd row), beside sorting and choosing the 1st row, could anyone help me with the MAX query.

that should work
select * from (select centre_name, sum(qty) as number1 from
(select exchange_from_centre_id as cenid, count(exchange_from_centre_id) as qty
from as2.exchange
group by exchange_from_centre_id
union all
select exchange_to_centre_id as cenid, count(exchange_to_centre_id) as qty
from as2.exchange
group by exchange_to_centre_id), as2.centre c
where c.centre_id = cenid
group by centre_name) where number1 = (select max(number1) from (select centre_name, sum(qty) as number1 from
(select exchange_from_centre_id as cenid, count(exchange_from_centre_id) as qty
from as2.exchange
group by exchange_from_centre_id
union all
select exchange_to_centre_id as cenid, count(exchange_to_centre_id) as qty
from as2.exchange
group by exchange_to_centre_id), as2.centre c
where c.centre_id = cenid
group by centre_name));

SQL Fiddle Demo
I use your result query instead of the big query to simplify the sample.
I update your sample to have 2 row with max value 6.
You calculate in a select the max value, and then join to the original table to bring all row matching that value
SELECT *
FROM (SELECT MAX(Score) Score
FROM Table1) as mV
INNER JOIN Table1 t
ON mv.Score = t.Score

Related

select value based on max of other column

I have a few questions about a table I'm trying to make in Postgres.
The following table is my input:
id
area
count
function
1
100
20
living
1
200
30
industry
2
400
10
living
2
400
10
industry
2
400
20
education
3
150
1
industry
3
150
1
education
I want to group by id and get the dominant function based on max area. With summing up the rows for area and count. When area is equal it should be based on max count, when area and count is equal it should be based on prior function (i still have to decide if education is prior to industry or vice versa). So the result should be:
id
area
count
function
1
300
50
industry
2
1200
40
education
3
300
2
industry
I tried a lot of things and maybe it's easy, but i don't get it. Can someone help to get the right SQL?
One method uses row_number() and conditional aggregation:
select id, sum(area), sum(count),
max(function) over (filter where seqnum = 1) as function
from (select t.*,
row_number() over (partition by id order by area desc) as seqnum
from t
) t
group by id;
Another method uses ``distinct on`:
select id, sum(area) over (partition by id) as area,
sum(count) over (partition by id) as count,
function
from t
order by id, area desc;
Use a scalar sub-query for "function".
select t.id, sum(t.area), sum(t.count),
(
select "function"
from the_table
where id = t.id
order by area desc, count desc, "function" desc
limit 1
) as "function"
from the_table as t
group by t.id order by t.id;
SQL Fiddle
you can use sum as window function:
select distinct on (t.id)
id,
sum(area) over (partition by id) as area,
sum(count) over (partition by id) as count,
( select function from tbl_test where tbl_test.id = t.id order by count desc limit 1 ) as function
from tbl_test t
This is how you get the function for each group based on id:
select id, function
from yourtable yt1
left join yourtable yt2
on yt1.id = yt2.id and yt1.area < yt2.area
where yt2.area.id is null;
(we ensure that no yt2 exists that would be of the same id but of higher areay)
This would work nicely, but you might have several max areas with different values. To cope with this isue, let's ensure that exactly one is chosen:
select id, max(function) as function
from yourtable yt1
left join yourtable yt2
on yt1.id = yt2.id and yt1.area < yt2.area
where yt2.area.id is null
group by id;
Now, let's join this to our main table;
select yourtable.id, sum(yourtable.area), sum(yourtable.count), t.function
from yourtable
join (
select id, max(function) as function
from yourtable yt1
left join yourtable yt2
on yt1.id = yt2.id and yt1.area < yt2.area
where yt2.area.id is null
group by id
) t
on yourtable.id = t.id
group by yourtable.id;

sql - select all rows that have all multiple same cols

I have a table with 4 columns.
date
store_id
product_id
label_id
and I need to find all store_ids that have all products_id with same label_id (for example 4)in one day.
for example:
store_id | label_id | product_id | data|
4 4 5 9/2
5 4 7 9/2
4 3 12 9/2
4 4 7 9/2
so it should return 4 because it's the only store that contains all possible products with label 4 at one day.
I have tried something like this:
(select store_id, date
from table
where label_id = 4
group by store_id, date
order by date)
I dont know how to write the outer query, I tried:
select * from table
where product_id = all(Inner query)
but it didnt work.
Thanks
It is unclear from your question whether the labels are specific to a given day or through the entire period. But a variation of Tim's answer seems appropriate. For any label:
SELECT t.date, t.label, t.store_id
FROM t
GROUP BY t.date, t.label, t.store_id
HAVING COUNT(DISTINCT t.product_id) = (SELECT COUNT(DISTINCT t2product_id)
FROM t t2
WHERE t2.label = t.label
);
For a particular label:
SELECT t.date, t.store_id
FROM t
WHERE t.label = 4
GROUP BY t.date,t.store_id
HAVING COUNT(DISTINCT t.product_id) = (SELECT COUNT(DISTINCT t2product_id)
FROM t t2
WHERE t2.label = t.label
);
If the labels are specific to the date, then you need that comparison in the outer queries as well.
Here is one way:
SELECT date, store_id
FROM yourTable
GROUP BY date, store_id
HAVING COUNT(DISTINCT product_id) = (SELECT COUNT(DISTINCT product_id)
FROM yourTable t2
WHERE t2.date = t1.date)
ORDER BY date, product_id;
This query reads in a pretty straightforward way, and it says to find every product, on some date, whose distinct product count is the same as the distinct product count on the same day, across all stores.
I'd probably aggregate to lists of products in a string or array:
with products_per_day_and_store as
(
select
store_id,
date,
string_agg(distinct product_id order by product_id) as products
from mytable
where label_id = 4
group by store_id, date
)
, products_per_day
(
select
date,
string_agg(distinct product_id order by product_id) as products
from mytable
where label_id = 4
group by date
)
select distinct ppdas.store_id
from products_per_day_and_store ppdas
join products_per_day ppd using (date, products);

select two grouped by columns but only select row with the highest COUNT()

I have a table that consists of three columns - UPC, ATTRIBUTE, STORE_NUM. I have 10 stores and 2 UPCs at each with different ATTRIBUTEs.
Every store either has either attribute X or Y. I group by UPC and ATTRIBUTE and get the count of stores.
SELECT [UPC], [ATTRIBUTE], COUNT([STORE_NUM]) AS [COUNT]
FROM TABLEA
GROUP BY [UPC], [ATTRIBUTE]
Yields this:
UPC ATTRIBUTE COUNT
1 X 8
1 Y 2
2 X 1
2 Y 9
And I want to select UPC and ATTRIBUTE with the highest count. My desired output would be this:
UPC ATTRIBUTE
1 X
2 Y
I can't figure out how to reach this desired outcome.
You can use window functions with aggregation:
SELECT *
FROM (SELECT [UPC], [ATTRIBUTE], COUNT(*) AS [COUNT],
ROW_NUMBER() OVER (PARTITION BY UPC ORDER BY COUNT(*) DESC) as seqnum
FROM TABLEA
GROUP BY [UPC], [ATTRIBUTE]
) x
WHERE seqnum = 1;
Use RANK() if you want duplicates in the event of ties.
Use row_number and a subquery:
SELECT UPC, ATTRIBUTE
FROM (
SELECT UPC, ATTRIBUTE, ROW_NUMBER() OVER (PARTITION BY UPC ORDER BY a_count DESC) as rn
FROM ( SELECT [UPC],[ATTRIBUTE],COUNT([STORE_NUM]) AS [a_COUNT]
FROM TABLEA
GROUP BY [UPC],[ATTRIBUTE]
) t
) q
WHERE q.rn = 1

SQL MIN(value) matching row in PostgreSQL

I have a following tables:
TABLE A:
ID ID NAME PRICE CODE
00001 B 1000 1
00002 A 2000 1
00003 C 3000 1
Here is the SQL I use:
Select Min (ID),
Min (ID NAME),
Sum(PRICE)
From A
GROUP BY CODE
Here is what I get:
ID ID NAME PRICE
00001 A 6000
As you can see, ID NAME don't match up with the min row value. I need them to match up.
I would like the query to return the following
ID ID NAME PRICE
00001 B 6000
What SQL can I use to get that result?
If you want one row, use limit or fetch first 1 row only:
select a.*
from a
order by a.price asc
fetch first 1 row only;
If, for some reason, you want the sum() of all prices, then you can use window functions:
select a.*, sum(a.price) over () as sum_prices
from a
order by a.price asc
fetch first 1 row only;
You can use row_number() function :
select min(id), max(case when seq = 1 then id_name end) as id_name, sum(price) as price, code
from (select t.*, row_number() over (partition by code order by id) seq
from table t
) t
group by code;
you can also use sub-query
select t1.*,t2.* from
(select ID,Name from t where ID= (select min(ID) from t)
) as t1
cross join (select sum(Price) as total from t) as t2
https://dbfiddle.uk/?rdbms=postgres_10&fiddle=a496232b552390a641c0e5c0fae791d1
id name total
1 B 6000

SQL SUM aggragete issue

ID Title Qty
1 BMW 2
2 VW 3
I want in one SQL query to find a sum of quantity and divide it by current Qty.
For example:
SUM (Qty) = 5, so I want to compute scores by formula. 2/5 and 3/5
ID title newscores
1 BMW 2/5
1 vW 2/5
Demo
SELECT id
,title
,qty/(select sum(qty) from cars)
FROM cars
GROUP BY id
this should work
select title , sum (QTY) , t2.total, sum(QTY) / t2.total
from table , (select sum(QTY) as total from table) as t2
group by title
SELECT ID, Title, CONCAT( Qty, '/', (SELECT SUM( Qty) FROM table1) ) AS 'newscores'
FROM `table1`
select id, title, qty/(select sum(qty) from make)
from make
See SQLFiddle.
Note there is no need whatsoever for a group by clause.