Question

我有三个表如下：

IDS：

id | id_code
1  | abcde
2  | jklmn
3  | pqrst

播放器：

full_name| initials
john s.  | js
anne p.  | ap
jen l.   | jl

游戏：

id     | player | points | player2 | points2
1      | js     | 2      | ap      | 1 
2      | ap     | 1      | jl      | 3 
2      | jl     | 3      | js      | 4 
3      | jl     | 4      | ap      | 1

==

我想获得以下输出：

id | id_code | full_name | points | full_name_player_2 | points2

我无法弄清楚如何使用多个连接语句来执行此操作...

Answer 1

这是连接表的示例，其中内部表的连接将加入游戏。

select p1.*, i1.*, g.*, p2.*, i2.* from 
games g inner join (player p1 inner join id i1 on p1.id = i1.id) 
    on g.player = p1.initials
inner join (player p2 inner join id i2 on p2.id = i2.id) 
    on g.player2 = p2.initials

Answer 2

<强>更新

使用新结构：

select i.id, i.id_code, p1.full_name, g.points, p2.full_name, g.points2
from 
    @ids as i
    inner join @games as g on g.id = i.id
    inner join @players as p1 on g.player = p1.initials
    inner join @players as p2 on g.player2 = p2.initials

OLD DATABASE

我认为这会得到你的结果。如果有效，请告诉我。

select i.id, i.id_code, p1.full_name, g.points, p2.full_name, g.points2
from 
    @ids as i
    inner join @players as p1 on p1.id = i.id
    inner join @games as g on g.player = p1.initials
    inner join @players as p2 on g.player2 = p2.initials

测试用例

declare @ids table (
    id int,
    id_code nvarchar(200)
)

declare @players table (
    id int,
    full_name nvarchar(200),
    initials nvarchar(200)
)

declare @games table (
    player nvarchar(200),
    points int,
    player2 nvarchar(200),
    points2 int
)

insert into @ids (id, id_code) values (1, 'abcde')
insert into @ids (id, id_code) values (2, 'jklmn')
insert into @ids (id, id_code) values (3, 'pqrst')


insert into @players (id, full_name, initials) values (1, 'john s.', 'js')
insert into @players (id, full_name, initials) values (2, 'anne p.', 'ap')
insert into @players (id, full_name, initials) values (3, 'jen l.', 'jl')


insert into @games (player, points, player2, points2) values ('js', 2, 'ap', 1)
insert into @games (player, points, player2, points2) values ('ap', 1, 'jl', 3)
insert into @games (player, points, player2, points2) values ('jl', 3, 'js', 4)
insert into @games (player, points, player2, points2) values ('jl', 4, 'ap', 1)

INNER在另一个列中的多个列上加入一列？

2 个答案: