使用LISTAGG获取值，但避免对内部联接中使用的表进行分组

Question

Hi I have an Oracle query like

select listagg(name,',') within group (order by name)
from table t1 
inner join table t2 on t1.id=t2.id
inner join table t3 on t1.value=t3.value

but later i needed to fetch 2 more columns from another table t4 so i joined t4 but when i join the listagg is giving repeated values separated with comma

select listagg(name,',') within group (order by name)
from table t1 
inner join table t2 on t1.id=t2.id
inner join table t3 on t1.value=t3.value
inner join table t4 on t1.id=t4.id

I want to fetch these new two columns without effecting the LISTAGG function.

Answer 1

By adding the joins you are getting names repeated in the results. Assuming your joins are correct, you could use DISTINCT to resolve this:

select listagg(name,',') within group (order by name)
from (select distinct name
      from table t1 
      inner join table t2 on t1.id=t2.id
      inner join table t3 on t1.value=t3.value
      inner join table t4 on t1.id=t4.id
)