I have two tables on MySQL (using phpMyAdmin), looking like the following:
Table 1:
Country Total Minutes
USA 100
USA 90
Canada 60
Mexico 80
UK 90
France 70
France 10
Germany 10
In Table 2, what I need to do is the following:
Region Total Minutes
North America USA+USA+Canada+Mexico Mins
Europe UK+France+France+Germany Mins
Is there a way to have a row be the result of a query?
You either need a region column in table 1:
SELECT region, SUM(`Total Minutes`)
FROM timespent
GROUP BY region;
Or a separate region <-> country table:
SELECT region, SUM(`Total Minutes`)
FROM myregions r
INNER JOIN timespent t USING (country)
GROUP BY r.region;
The regions table would look like this:
region | country
--------------+--------
North America | USA
North America | Mexico
If you can't change anything in your database, look at Andomar's solution :)
You could translate the countries to regions in a subquery. The outer query can then group by on region:
select Region
, sum(TotalMinutes) as TotalMinutes
from (
select case country
when 'USA' then 'North America'
when 'France' then 'Europe'
end as Region
, TotalMinutes
from YourTable
) as SubQueryAlias
group by
Region
Related
I have recently attended an interview on SQL. Below is the question:
Write a query to retrieve city name, state name, city population and return the following calculations along with the before mentioned fields.
Average city population in the state.
Difference between the city population and average city population in that state.
City Table:
City_Name
State_NAme
Population
Baltimore
Maryland
30000
College Park
Maryland
18000
Columbia
Maryland
20000
Boston
Massachusetts
35000
Malden
Massachusetts
10000
Dover
Delaware
20000
Jersey City
New Jersey
35000
I have tried below query but I didnot get desired output. Can anyone help me with correct query?
select * from city_table;
select state_name, sum(population)/count(city_name) as average_city_pop
from city_table
group by state_name;
You need to explore sql more, learn about aggregation functions and joins. Your query is correct in obtaining the average population. You need to join it to the original table to get your result.
with avg_city_pop as (select state_name, avg(population) as avg from city group by state_name)
select c.*, acp.avg as average_city_population, abs(acp.avg-c.population) as difference from city c inner join avg_city_pop acp on c.state_name = acp.state_name;
try it out here
For MySQL versions before 8.0, we can use a correlated subquery to get the average population for each state, which can alss be used to calculate the gap between city population and state average population. Note, the abs function is optionally used to always return a positive number. Omit it if necessary.
select city_name,state_name,(select avg(population) from city where state_name=c.state_name group by state_name ) as average_pop ,
abs(population - (select avg(population) from city where state_name=c.state_name group by state_name )) as gap_pop
from city c;
select
city_name,
state_name,
population,
avg(population) over (partition by state_name) as Avg_pop,
population-avg(population) over (partition by state_name) as Difference
from city;
see sqlfilldle: https://www.db-fiddle.com/f/tVxdH6bQvsu48umWgLmrQB/0
This needs MySQL 8.0+, because over_clause is available since 8.0.
output:
city_name
state_name
population
Avg_pop
Difference
dover
delaware
20000
20000.0000
0.0000
baltimore
maryland
30000
22666.6667
7333.3333
college park
maryland
18000
22666.6667
-4666.6667
columbia
maryland
20000
22666.6667
-2666.6667
boston
massachussets
35000
22500.0000
12500.0000
molden
massachussets
10000
22500.0000
-12500.0000
jersey city
new jersey
35000
35000.0000
0.0000
Sql question:
enter image description here
competitor country
Acme Corp USA
GLOBEX USA
Openmedia France
K-bam USA
Hatdrill UK
Hexgreen Germany
D-ranron France
Faxla Spain
the output should be
country competitors
France 2
Germany 1
Spain 1
UK 1
USA 3
Total: 8
except using groupby with rollup, i am trying to solve it via "union" but turns out "order by is not functioning" (supposed to order by country name, but my output turns out to "order by competitors" ...)
This is my code:
(select country, count(competitor) as competitors
from table
group by 1
order by 1
)
union all
(select "Total:" as country, count(*) as competitors from table);
Any help would be appreciated! Thank you!
If you want the result ordered, you need an order by after the union:
(select country, count(competitor) as competitors
from table
group by 1
) union all
(select 'Total:' as country, count(*) as competitors
from table
)
order by (country = 'Total:') desc, country asc
The table name is c_list.
Country City Rating Date
------------------------------------
France Brest 95 24092016
France Brest 98 27092016
France Brest 95 03102016
France Lille 100 26092016
France Lille 92 28092016
Japan Tokyo 98 02102016
There are more than 50 different countries and each country have few cities. And each city may have more than one row of record or more. I want to select one City with highest average Rating (Compare to Cities in it's own country) and then compare with all other cities in different countries. So, the final query should display all Country and their ONE City with max(avg(Rating)) and in desc order. The sample output:
Country City max(avg(rating))
-------------------------------------
USA New York 97.25
UK Cardiff 96.70
Germany Greven 96.50
Turkey Afyon 94.88
France Guipavas 94.10
Canada Cartwright 91.35
I can only get the max(avg(rating)) for one country. Need help.
SELECT top 1 country, city, Avg(rating) AS Ratings
FROM c_list
where country = 'France'
GROUP BY city, country
order by Ratings desc
(Edited) The result that I want is similar like Miss world contest. Compete and win against local contestant in your country first. Next (my final result set) is to compete against the winners from other countries and rank them first to last using their avg(rating) that they got eatlier in their country.
If am not wrong you are looking for this
SELECT country,
city,
Avg(rating) AS Ratings
FROM c_list A
GROUP BY city,
country
HAVING Avg(rating) = (SELECT TOP 1 Avg(rating) AS Ratings
FROM c_list B
WHERE a.country = b.country
GROUP BY city
ORDER BY ratings DESC)
ORDER BY ratings DESC
Note : If you are using Mysql the replace TOP keyword with LIMIT
Base table:
select t.* from temp_lax t
COUNTRY CITY RATING
1 France Brest 95
2 France Brest 98
3 France Brest 95
4 France Lille 100
5 France Lille 92
6 Japan Tokyo 98
Query:
select t1.country, t1.city, Avg(t1.Rating) rating
from temp_lax t1
group by t1.country, t1.city
having avg(t1.rating) = (select max(avg(rating))
from temp_lax t2
WHERE t1.country = t2.country
GROUP BY t2.city)
order by rating desc
OUTPUT:
COUNTRY CITY RATING
1 Japan Tokyo 98
2 France Lille 96
3 France Brest 96
Please let me know if you are looking for different result set.
So, for example i've got the following table;
ID COUNTRY VALUE
--------------------- -------------------- --------------------
1 India 12000
2 India 11000
3 UK 11000
4 India 15000
5 Canada 11000
And I would like to group by Country but only have the country with the highest value show up, if I would just use a group by query like:
SELECT * FROM countries GROUP BY country
I would get;
ID COUNTRY VALUE
--------------------- -------------------- --------------------
1 India 12000
3 UK 11000
5 Canada 11000
Where the value for india would be 12000. I would like the query to group on the highest value for the group by on country like:
ID COUNTRY VALUE
--------------------- -------------------- --------------------
3 UK 11000
4 India 15000
5 Canada 11000
So it's grouped on the highest value which is 15000.
DEMO
SELECT s1.ID, s1.COUNTRY, s1.VALUE
FROM countries s1
LEFT JOIN countries s2
ON s1.VALUE < s2.VALUE
AND s1.COUNTRY = s2.COUNTRY
WHERE s2.COUNTRY IS NULL;
OUTPUT
NOTE: But be carefull of ties. In that case you can get one random from those ties.
You can use the MAX aggregate function.
select
country,
max(value) value
from countries
group by
country
See the live example.
Edit: The original solution was only correct due to the nature of the data. I've removed the ID from the first query, to correct the mistake. Here is another solution (based on #Juan Carlos Oropeza's work - thank you) that will return the ID and eliminate the ties.
select
min(x.id) id,
x.country,
x.value
from (
select
c.*
from countries c
left join countries c1 on c.value < c1.value and c.country = c1.country
where c1.country is null
) x
group by
x.country,
x.value
;
See the live example - I've modified the data to cover edge cases mentioned above.
I hope you can help me with an SQL statment that I can't seem to figure out.
I have a table with a list of visits made, with the country visited and the dates such as;
United Kingdom, 1st Nov 2009
Germany, 8th June 2010
Frane, 10th September 2011
United Kingdom, 11th october 2011
etc.
I want to extract the data so that I get a table list such as follows
Times Visited - Country list
23 - United Kingdom
10 - France, Germany
4 - Czech Republic, USA, Canada
1 - Poland, Serbia, Argentina, New Zealand
So that the data shows that I have made 4 visist to the Czech Republic, USA & Canda
And the query
select * from
(
select count(*) as "trips", country from trip_view
group by country
order by 1 desc
) as a
returns the data
23 United Kingdom
10 France
10 Germany
4 Czech Republic
4 USA
4 Canada
etc.
So I need a kind of group on the outer SQL, but if I do the following
select * from
(
select count(*) as "trips", country from trip_view
group by country
order by 1 desc
) as a
group by trips
Then I only get 1 entry for each country. i.e.
23 United Kingdom
10 France
4 Czech Republic
etc.
So for each row I only have 1 country listed and not all of them. i.e. Row 2 should show France & Germany and row 3 should show Czech, USA & Canada
Any ideas how to do this in mysql?
Thanks
Using GROUP_CONCAT on the country column it should yield the result you want:
SELECT trips,
GROUP_CONCAT(country) AS country
FROM (
SELECT COUNT(*) AS "trips",
country
FROM trip_view
GROUP BY country
) a
GROUP BY trips
ORDER BY 1 DESC
Output:
TRIPS COUNTRY
23 United Kingdom
10 France,Germany
4 Czech Republic,Canada,USA
Live DEMO.