listagg Oracle SQL 查询，加入同一张表

Question

对于每只狗，我想查找除狗之外的其他动物的匹配名称，并将它们添加到逗号分隔的列表中。表格图片及查询结果如下：

存在具有以下结构的表：

我想创建一个查询结果，例如：

Answer 1

您可以使用self-join，然后使用listagg。

select tdog.animal,tdog.name
,listagg(tother.animal||'-'||tother.name||'-'||tother.id) within group(order by tother.id)
from tablename tdog
join tablename tother on tdog.name=tother.name and tdog.animal='dog' and tother.animal <> 'dog'
group by tdog.animal,tdog.name

Answer 2

有了一些技巧，你就不需要self join：

select 'dog' as animal, name,
       listagg(case when animal <> 'dog' then animal || '-' || name || '-' || id
               end), ',') within group (order by id) as animals
from t
group by name
having sum(case when animal = 'dog' then 1 else 0 end) > 0