How to get the sum of country values and have them only appear once-CodePudding

I have my current sql query which I will later convert to a HIVE query.

SELECT home_team, COUNT(home_team) 
from results 
WHERE results.home_score < results.away_score 
GROUP BY home_team 
UNION 
SELECT away_team, COUNT(away_team) 
FROM results 
WHERE results.away_score < results.home_score 
GROUP BY away_team

And it currently returns two occurrences of a country, once as a home_team and once as an away_team. Current results

How can I modify this query so it adds the count(home_team) and makes the country only appear once? Ex. Argentina : 50

I've tried to put both select queries in brackets and then count the sum being returned but I seem to always get an error when I do order by.

CodePudding user response：

This should resolve your issue

-- Create a temporary table
WITH counted AS (
    SELECT home_team, COUNT(home_team) AS row_nb FROM results WHERE results.home_score < results.away_score GROUP BY home_team
    UNION
    SELECT away_team, COUNT(away_team) FROM results WHERE results.away_score < results.home_score GROUP BY away_team
)
-- And then sum the row_nb
SELECT home_team, SUM(row_nb) FROM counted;

CodePudding user response：

After unioning the results, aggregate by team and add up the lost games with SUM.

And you must use UNION ALL instead of UNION [DISTINCT]. Otherwise, for a team that lost five games at home and five games away, five games will only counted once instead of twice. (I.e. the team will be shown with five lost games instead of with the ten games they really lost.)

Remember: UNION removes duplicates and is very seldom needed. UNION ALL is used more often.

SELECT team, SUM(lost) AS lost_games
FROM
(
  SELECT home_team AS team, COUNT(*) AS lost
  FROM results 
  WHERE home_score < away_score 
  GROUP BY home_team 
  UNION ALL
  SELECT away_team AS team, COUNT(*) AS lost
  FROM results 
  WHERE away_score < home_score 
  GROUP BY away_team
)
GROUP BY team
ORDER BY team;