Concat two subqueries into one column - sql

Question

I'm trying to concat two of my subqueries together.
Is there a trick to allow this to happen? It doesn't like my '||' after the first subquery
Select
pi.name || ',' || pi.lastName || ',' ||
(select middleName from MiddleNameTable where id = pi.id) MiddleName || ','
|| (select formalName from formalName where id = pi.id) formalName
from
mytable pi

Answer 1

I was dumb, I don't need the middleName Alias
I should just it without the middle alias since i'm joining all together anyway
Select pi.name || ',' || pi.lastName || ',' ||
(select middleName from MiddleNameTable where id = pi.id) || ','
||(select formalName from formalName where id = pi.id) as fullName
from mytable pi

Answer 2

Well, yes - you can do it if syntax is correct (sample data in lines #1 - 7; query begins at line #8):
SQL> with
2 mytable (id, name, lastname) as
3 (select 1, 'Brand', 'Erson' from dual),
4 middlenametable (id, middlename) as
5 (select 1, 'S' from dual),
6 formalname (id, formalname) as
7 (select 1, 'Overflow' from dual)
8 Select pi.name || ',' || pi.lastName || ',' ||
9 (select m.middleName from MiddleNameTable m where m.id = pi.id) || ','
10 ||(select f.formalName from formalName f where f.id = pi.id) as full_name
11 from mytable pi;
FULL_NAME
----------------------
Brand,Erson,S,Overflow
But, why would you do it that way? What's wrong with a simple join?
SQL> with
2 mytable (id, name, lastname) as
3 (select 1, 'Brand', 'Erson' from dual),
4 middlenametable (id, middlename) as
5 (select 1, 'S' from dual),
6 formalname (id, formalname) as
7 (select 1, 'Overflow' from dual)
8 select pi.name ||','|| pi.lastname ||','|| m.middlename ||','|| f.formalname as full_name
9 from mytable pi left join middlenametable m on m.id = pi.id
10 left join formalname f on f.id = pi.id;
FULL_NAME
----------------------
Brand,Erson,S,Overflow
SQL>

Answer 3

I show you my option, maybe you'll think why you need CONCAT function if it is only for two arguments...
I use it sometimes because is more clean.
The point is there, is CONCAT accept only two arguments, but you can do nested function.
SELECT
'PERICO' || ',' ||
'DE' || ',' ||
CONCAT(
(SELECT 'LOS' || ',' FROM DUAL),
(SELECT 'PALOTES' FROM DUAL))
FROM DUAL;
Or
SELECT
CONCAT(
CONCAT('PERICO' || ',',
'DE' || ',')
,
CONCAT(
(SELECT 'LOS' || ',' FROM DUAL),
(SELECT 'PALOTES' FROM DUAL))
)
FROM DUAL;
result --> PERICO,DE,LOS,PALOTES