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select*from player, team whereplayer.team_id=team.team_id;
非等值连接
selectp.player_nameas name,
p.height, h.height_levelfrom player as p, height_grades as h
wherep.height between h.height_lowestandh.height_highestorder byp.heightdesc;
外连接
左连接:指的是左边的是主表
SELECT*FROM player LEFT JOIN team onplayer.team_id=team.team_id;
select*from player left join player_score onplayer.player_id=player_score.player_id;
同理 右连接表示右边是主表
select*from player, team whereplayer.team_id(+) =team.team_id; # (+)表示主表select*from player right join team onplayer.team_id=team.team_id;
自连接
selectb.player_name, b.heightfrom player as a , player as b wherea.player_name='布雷克-格里芬'anda.height<b.height
The text was updated successfully, but these errors were encountered:
笛卡尔积
等值连接
非等值连接
外连接
左连接:指的是左边的是主表
同理 右连接表示右边是主表
自连接
The text was updated successfully, but these errors were encountered: