Android:一个光标行用于两个连接的表
我有两张桌子,让我们称之为比赛和团队。比赛与球队有一对二的关系 火柴Android:一个光标行用于两个连接的表,android,sqlite,android-cursor,Android,Sqlite,Android Cursor,我有两张桌子,让我们称之为比赛和团队。比赛与球队有一对二的关系 火柴 _id = INTEGER PRIMARY time = TEXT NOT NULL team1_id = TEXT NOT NULL //references a team record team2_id = TEXT NOT NULL //references a team record 团队有 _id = INTEGER PRIMARY name = TEXT NOT NULL 我的列表中的每个项目都包含时间、团队1
_id = INTEGER PRIMARY
time = TEXT NOT NULL
team1_id = TEXT NOT NULL //references a team record
team2_id = TEXT NOT NULL //references a team record
团队有
_id = INTEGER PRIMARY
name = TEXT NOT NULL
我的列表中的每个项目都包含时间、团队1\u名称和团队2\u名称。由光标填充。它看起来像这样:
现在,当我使用联接查询时:
Select match._id, time, team.name
From match LEFT JOIN team
ON (team._id = match.team1_id OR team._id = match.team2_id)
我收到以下光标结果:
_id time name
42 6:00 Barca
42 6:00 Man City
我试图实现的是将两个团队名称放在光标的两列中,而不是单独的行中,以便将其映射到适配器的视图,即:
_id time team1 team2
42 6:00 Barca Man City
有什么建议吗?
谢谢。您需要进行多个联接并为列名别名:
SELECT match._id,
time,
t1.name AS team1_name,
t2.name AS team2_name
FROM match
LEFT JOIN team AS t1 ON (t1._id = match.team1_id)
LEFT JOIN team AS t2 ON (t2._id = match.team2_id)
您需要进行多个联接并为列名命名:
SELECT match._id,
time,
t1.name AS team1_name,
t2.name AS team2_name
FROM match
LEFT JOIN team AS t1 ON (t1._id = match.team1_id)
LEFT JOIN team AS t2 ON (t2._id = match.team2_id)
@Rotwang INNER也给了我两个rows@Rotwang内里也给了我两行