Outer join removing duplicated columns - sql

Question

I'm trying to joint multiple data obtained trough a query like this:
select
TO_VARCHAR(CREATE_TIME, 'yyyy-MM') as YEAR_MONTH,
COUNT(1) as DESIRED_VALUE
from
MY_TABLE
where
FIELD = 'DESIRED_VALUE'
group by 1;
That results in data such as:
YEAR DESIRED_VALUE1
2022-09 52
2022-10 117
2022-11 95
2023-01 73
YEAR_MONTH DESIRED_VALUE2
2022-11 35
2022-12 30
2023-01 29
I want to end up with a table such as:
YEAR_MONTH DESIRED_VALUE1 DESIRED_VALUE2
2022-09 52 NULL
2022-10 117 NULL
2022-11 95 35
2022-12 53 30
2023-01 73 29
I don't have previous knowledge of which dates will be returned by each query, if that makes sense, so I can't infer if it's a left join, for instance. So I'm doing a full
with result_1 as
(
query1
),
result_2 as
(
query2
)
select *
from
result_1
full outer join result_2
on
result_1.YEAR_MONTH = result_2.YEAR_MONTH
Which gives me this:
YEAR_MONTH DESIRED_VALUE2 YEAR_MONTH_2 DESIRED_VALUE1
2023-01 29 2023-01 73
NULL NULL 2022-10 117
2022-11 35 2022-11 95
NULL NULL 2022-09 52
2022-12 30 NULL NULL
But I want do display a single YEAR_MONTH column, that shows all existent values:
YEAR_MONTH DESIRED_VALUE2 DESIRED_VALUE1
2023-01 29 73
2022-10 NULL 117
2022-11 35 95
2022-09 NULL 52
2022-12 30 NULL
To resolve that, I use:
COALESCE(DESIRED_VALUE1.YEAR_MONTH, DESIRED_VALUE2.YEAR_MONTH) as YEAR_MONTH
However, if I add more data:
with result_1 as
(
select
TO_VARCHAR(CREATE_TIME, 'yyyy-MM') as YEAR_MONTH,
COUNT(1) as DESIRED_VALUE1
from
MY_TABLE
where
STATUS = 'DESIRED_VALUE1'
group by 1
),
result_2 as
(
select
TO_VARCHAR(CREATE_TIME, 'yyyy-MM') as YEAR_MONTH,
COUNT(1) as DESIRED_VALUE2
from
MY_TABLE
where
STATUS = 'DESIRED_VALUE2'
group by 1
),
result3 as
(
select
TO_VARCHAR(CREATE_TIME, 'yyyy-MM') as YEAR_MONTH,
COUNT(1) as DESIRED_VALUE3
from
MY_TABLE
where
STATUS = 'DESIRED_VALUE3'
and CONDITION = 'CONDITION'
group by 1
)
select
COALESCE(DESIRED_VALUE1.YEAR_MONTH, DESIRED_VALUE2.YEAR_MONTH, DESIRED_VALUE3.YEAR_MONTH) as YEAR_MONTH,
DESIRED_VALUE1,
DESIRED_VALUE2,
DESIRED_VALUE3
from
result_1
full outer join
result_2
on
result_1.YEAR_MONTH = result_2.YEAR_MONTH
full outer join
result_3
on
result_2.YEAR_MONTH = result_3.YEAR_MONTH
order by YEAR_MONTH desc;
I start getting repeated YEAR_MONTH
YEAR_MONTH DESIRED_VALUE1 DESIRED_VALUE2 DESIRED_VALUE3
2023-01 73 29 83
2022-12 53 30 57
2022-11 95 35 71
2022-10 NULL 39 NULL
2022-10 117 NULL NULL
2022-09 18 NULL NULL
2022-09 52 NULL NULL
I'm not sure what's the best way to approach this problem.

Answer 1

If correctly understand what you're trying to accomplish, wouldn't it be a whole lot simpler (and a lot more performant) to just say
select to_varchar(CREATE_TIME, 'yyyy-MM') as YEAR_MONTH,
sum( case STATUS when 'DESIRED_VALUE1' then 1 else 0 end ) as DESIRED_VALUE1,
sum( case STATUS when 'DESIRED_VALUE2' then 1 else 0 end ) as DESIRED_VALUE2,
sum( case STATUS when 'DESIRED_VALUE3' then 1 else 0 end ) as DESIRED_VALUE3
from MY_TABLE
where STATUS in ('DESIRED_VALUE1, DESIRED_VALUE2, DESIRED_VALUE3 )
group by 1
order by 1

Answer 2

try this
;with cte(date, value1, value2) as(
select date, value1, null from query1
union
select date, null, value2 from query2
)
select date
, sum(value1)
, sum(value2)
from cte
group by date