Database PostgreSQL:对共享字段的值求和
对于PostgreSQL 9.3.1中给定的奥运选手模式Database PostgreSQL:对共享字段的值求和,database,postgresql,sum,Database,Postgresql,Sum,对于PostgreSQL 9.3.1中给定的奥运选手模式 Olympics ( athlete varchar(33), age int, country varchar(21), year int, closing_ceremony_date timestamp, sport varchar(25), gold_medals int, silver_medals int, bronze_medals int
Olympics (
athlete varchar(33),
age int,
country varchar(21),
year int,
closing_ceremony_date timestamp,
sport varchar(25),
gold_medals int,
silver_medals int,
bronze_medals int,
total_medals int
)
它列出了不同的奥运选手、他们参加比赛的年份以及他们获得的奖牌。然而,重复参加奥运会的运动员可能在不同的年份获得了奖牌,我需要知道每个运动员总共获得了多少枚奖牌。谢谢 您将需要执行类似以下示例的操作
Select athlete, sum(gold_medals) + sum(silver_medals) + sum(bronze_medals)
from Olympics group by athlete
或者,如果字段total\u
填充正确,您可以直接选择它:
Select athlete, sum(total_medals )
from Olympics group by athlete