如何从另一个表SQL Server查询中选择2个变量

Question

好了，这里的问题

表1 ：

Id1, Id2

表2

Id, Username

现在，此Table 1 Id1和Id2变量是Table 2中的唯一键

我想选择Table 1所有值，因为

Username1, Username2

那么我怎么写这个查询呢？

完整的例子

表格1

1,3
3,5

表2

1,Furkan
3,Obama
5,USA

结果

Furkan, Obama
Obama, USA

谢谢

Answer 1

SELECT table2_1.Username AS Username1, table2_2.Username AS Username2
FROM table1
JOIN table2 AS table2_1 ON table1.Id1 = table2_1.Id
JOIN table2 AS table2_2 ON table1.Id2 = table2_2.Id

Answer 2

有关实时示例，请参见SQL Fiddle

SELECT a.Username AS name_1, b.Username AS name_2 FROM
  t1 JOIN t2 AS a ON t1.Id1 = a.Id
     JOIN t2 AS b ON t1.Id2 = b.Id

Answer 3

尝试这个

这是http://www.sqlfiddle.com/#!2/e10b7/2/0

CREATE TABLE table1
(
     Id1 int  primary key, 
     Id2 int
);

INSERT INTO table1
VALUES (1, 3),
       (3, 5);

CREATE TABLE table2
(
     Id int  primary key, 
     Username varchar(255)
);

INSERT INTO table2
VALUES (1, 'Furkan'),
       (3, 'Obama'),
       (5, 'USA');

您的SQL查询

select 
    (select Username 
     from table2 as t2 
     where t2.Id = t1.Id1) as coloum1 ,
    (select Username 
     from table2 as t2 
     where t2.Id = t1.Id2) as coloum2 
from table1 as t1