从两列中选择？

Question

CREATE TABLE Player
(playerID CHAR(3) ,
name CHAR(36),
year NUMBER,
team CHAR(50),
totalNoms NUMBER,
awardsWon NUMBER)

如何创建一个查询，从数据库中选择两列（团队和队员）？

Answer 1

取决于你想要做什么

select team, count(PlayerID) as NoOfPlayers
from Player
where team = 'Lackers'

或

select team, count(PlayerID) as NoOfPlayers
from Player
group by team

Answer 2

 SELECT team,COUNT(playerID) As NoOfPlayers from Player group by team

Answer 3

Select distinct p.team, (
Select count(*) from Player where team=p.team
) 
from Player p

输出将是（例如）：

• Team1 25
• Team2 34
• Team3 11