Hive query to get max of count

问题

My input file is like this:

id,phnName,price,model
1,iphone,2000,abc
2,iphone,3000,abc1
3,nokia,4000,abc2
4,sony,5000,abc3
5,nokia,6000,abc4
6,iphone,7000,abc5
7,nokia,8500,abc6

I want to write a hive query to get the max count of a particular phone.

output:

iphone 3
nokia 3

till now I've tried the following query:

select d.phnName,count(*) from phnDetails d group by d.phnName

and got output like this:

iphone 3
nokia 3
sony 1

Help me to retrieve only the max value.

回答1:

I have the query working

Input

1,iphone,2000,abc
2,iphone,3000,abc1
3,nokia,4000,abc2
4,sony,5000,abc3
5,nokia,6000,abc4
6,iphone,7000,abc5
7,nokia,8500,abc6

Working Query

select c.phnName, c.counter 
from 
(select d.phnName as phnName, count(*) as counter from phnDetails d group by d.phnName ) c 
join 
(select max(f.counter) as countmax from
(select cnt.phnName as phnName, count(*) as counter from phnDetails cnt group by cnt.phnName ) f) g 
where c.counter = g.countmax;

Not sure if it is optimized however it is working as expected

Output as below,

Solved using the steps as below, If it answers your question please mark it as answered

CREATE TABLE phnDetails ( id INT, phnName STRING, price INT, details STRING)
ROW FORMAT DELIMITED FIELDS TERMINATED BY ',' STORED AS TEXTFILE;

LOAD DATA LOCAL INPATH '/home/training/Phone/phones.txt' OVERWRITE INTO TABLE phnDetails;

select * from phnDetails;


select d.phnName, count(*) from phnDetails d group by d.phnName;


select c.phnName, c.counter from 
(select d.phnName as phnName, count(*) as counter from phnDetails d group by d.phnName ) c ;

select max(f.counter) as countmax from
(select cnt.phnName as phnName, count(*) as counter from phnDetails cnt group by cnt.phnName ) f ;

select max(f.counter) as countmax from
(select cnt.phnName as phnName, count(*) as counter from phnDetails cnt group by cnt.phnName ) f ;

select c.phnName, c.counter 
from 
(select d.phnName as phnName, count(*) as counter from phnDetails d group by d.phnName ) c 
join 
(select max(f.counter) as countmax from
(select cnt.phnName as phnName, count(*) as counter from phnDetails cnt group by cnt.phnName ) f) g 
where c.counter = g.countmax;

来源：https://stackoverflow.com/questions/24756744/hive-query-to-get-max-of-count

标签

Hive

bigdata

hiveql