sql - SQL连接两个表，并在两个表之间建立链接表-GORM/Grails

Question

我试图建立这样的输出:

Name source source source
Tim  Other  TV      Radio

我想将Person表和Source表结合在一起的地方:

Person
ID Name
1  Tim

Source
ID Name
1  Other
2  TV
3  Radio

Person_Source
p_id  s_id
 1     1
 1     2

我有一个查询，它建立了每个时间源并以多行输出。我正在结果集中寻找一个结果

select source.name
from person left join person_source
on person_source.person_source_id = person.id join source
on source.id = person_source.source_id

Answer 1

您可以在查询中添加DISTINCT:

select DISTINCT source.name
from person left join person_source
on person_source.person_source_id = person.id join source
on source.id = person_source.source_id