如何僅在sql中獲取值？

Question

所以我寫的SQL代碼讓球員只有在球隊2：

SELECT PlayerID from Player 
WHERE EXISTS 
(SELECT * from Team WHERE team.PlayerID = Player.PlayerID AND Team.TeamID = 't002'); 

的問題是，我忘了，有可能是情況下，球員也是其他球隊，所以任何想法如何解決這個問題？

Answer 1

使用的，而不是在

SELECT PlayerID from Player 
WHERE PlayerID in ( 
     SELECT team.PlayerID from Team WHERE Team.TeamID = 't002' 
) 
AND not in (
     SELECT team.PlayerID from Team WHERE Team.TeamID != 't002' 
) 
; 

Answer 2

應該使用加入，而不是

SELECT PlayerId FROM Player JOIN Team 
WHERE Team.PlayerId = Player.PlayerId AND Team.TeamId = 't002' 
AND NOT IN (SELECT team.PlayerID FROM Team 
WHERE Team.TeamId != 't002');