UNION on 2 joined queries - sql

Question

I have 2 working queries that are joined by subselects using WITH in DB2.
They each work separately but I can't seem to find the best way to properly combine or union them.
The first query:
with c as(
select
employee,
sum(salesPrice) as priorSpecifics
from schema1.orders g
inner join dateSchema.dates d
on g.dateField = d.dateField
where d.newDate between '2018-01-01' and '2018-01-31'
and g.details = 'CategoryOne'
group by employee
), d as(
select
employee,
sum(salesPrice) as priorTotals
from schema1.orders g
inner join dateSchema.dates d
on g.dateField = d.dateField
where d.newDate between '2018-01-01' and '2018-01-31'
group by employee
)
Select ifnull(c.employee,d.employee) as employee
,c.priorSpecifics
,d.priorTotals
,cast(Round((DEC(c.priorSpecifics,12,2)/DEC(d.priorTotals,12,2)) * 100,2) as decimal(12,2)) as priorPercent
from c full join d ON (c.employee = d.employee);
Returns 4 columns
and the 2nd query
with c as(
select
employee,
sum(salesPrice) as currentSpecifics
from schema1.orders g
inner join dateSchema.dates d
on g.dateField = d.dateField
where d.newDate between '2019-01-01' and '2019-01-31'
and g.details = 'CategoryOne'
group by employee
), d as(
select
employee,
sum(salesPrice) as currentTotals
from schema1.orders g
inner join dateSchema.dates d
on g.dateField = d.dateField
where d.newDate between '2019-01-01' and '2019-01-31'
group by employee
)
Select ifnull(c.employee,d.employee) as employee
,c.currentSpecifics
,d.currentTotals
,cast(Round((DEC(c.currentSpecifics,12,2)/DEC(d.currentTotals,12,2)) * 100,2) as decimal(12,2)) as currentPercent
from c full join d ON (c.employee = d.employee);
Returns 4 as well. The field employee is the only thing that is shared between all.
How can I combine this into one query to get one employee column and then all of my sum/percent columns following?

Answer 1

I think you can do everything you want with conditional aggregation:
select employee,
sum(case when d.newDate between '2018-01-01' and '2018-01-31' and g.details = 'CategoryOne' then salesPrice end) as priorSpecifics,
sum(case when d.newDate between '2019-01-01' and '2019-01-31' and g.details = 'CategoryOne' then salesPrice end) as currentSpecifics,
sum(case when d.newDate between '2018-01-01' and '2018-01-31' then salesPrice end) as priorTotals,
sum(case when d.newDate between '2019-01-01' and '2019-01-31' then salesPrice end) as currentTotals
from schema1.orders g inner join
dateSchema.dates d
on g.dateField = d.dateField
group by employee;
I'll let you fill in with the additional calculations.

Answer 2

If all the above queries are working then you already have everything you need.
You must combine from the 1st group, the first 2 to make the prior query, then
from the 2nd group to make the cur query
and finally join the prior query to the cur query:
with
c as(
select
employee,
sum(salesPrice) as priorSpecifics
from schema1.orders g
inner join dateSchema.dates d
on g.dateField = d.dateField
where d.newDate between '2018-01-01' and '2018-01-31'
and g.details = 'CategoryOne'
group by employee
),
d as(
select
employee,
sum(salesPrice) as priorTotals
from schema1.orders g
inner join dateSchema.dates d
on g.dateField = d.dateField
where d.newDate between '2018-01-01' and '2018-01-31'
group by employee
),
prior as (
Select ifnull(c.employee,d.employee) as employee
,c.priorSpecifics
,d.priorTotals
,cast(Round((DEC(c.priorSpecifics,12,2)/DEC(d.priorTotals,12,2)) * 100,2) as decimal(12,2)) as priorPercent
from c full join d ON (c.employee = d.employee)
),
e as(
select
employee,
sum(salesPrice) as currentSpecifics
from schema1.orders g
inner join dateSchema.dates d
on g.dateField = d.dateField
where d.newDate between '2019-01-01' and '2019-01-31'
and g.details = 'CategoryOne'
group by employee
),
f as(
select
employee,
sum(salesPrice) as currentTotals
from schema1.orders g
inner join dateSchema.dates d
on g.dateField = d.dateField
where d.newDate between '2019-01-01' and '2019-01-31'
group by employee
),
cur as (
Select ifnull(e.employee,f.employee) as employee
,e.currentSpecifics
,f.currentTotals
,cast(Round((DEC(e.currentSpecifics,12,2)/DEC(f.currentTotals,12,2)) * 100,2) as decimal(12,2)) as currentPercent
from e full join f ON (e.employee = f.employee)
)
Select ifnull(p.employee, c.employee) as employee
,p.priorSpecifics
,p.priorTotals
,p.priorPercent
,c.currentSpecifics
,c.currentTotals
,c.currentPercent
from prior p full join cur c ON (c.employee = c.employee);