db2 query for multiple cases - sql

Question

I have three queries below (identical except for the first line of the WHERE clauses) that all work perfectly in my script. The first one queries orders for a customer, the 2nd for all orders assigned to a representative and the third are all orders period, across the whole company.
Again, they all work given their respective variables (all variables come from the same page) but I'm trying to fill columns on a table for all 3 cases.
Is there a way I can combine these and create one query that gives me the same values for each respective clause?
So, I would expect all 6 columns returned for one query. This is running on db2 so I don't know the best way to proceed but could I create a larger CASE based query?
//query on orders for this customer
SELECT
count(*) as sales_180Cust,
180/count(*) as velocityCust
FROM orders g
inner join dates i
on g.date1 = i.acyyyymmdd
WHERE g.cust = $customer
AND g.frm = $frm
AND g.cvr = $cvr
AND g.clr = $clr
AND i.aciso between current_Date - 180 DAY AND current_Date;
//orders belonging to representative
SELECT
count(*) as sales_180Rep,
180/count(*) as velocityRep
FROM orders g
inner join dates i
on g.date1 = i.acyyyymmdd
WHERE g.rep = $rep
AND g.frm = $frm
AND g.cvr = $cvr
AND g.clr = $clr
AND i.aciso between current_Date - 180 DAY AND current_Date;
//query across ALL orders
SELECT
count(*) as sales_180Company,
180/count(*) as velocityCompany
FROM orders g
inner join dates i
on g.date1 = i.acyyyymmdd
WHERE g.frm = $frm
AND g.cvr = $cvr
AND g.clr = $clr
AND i.aciso between current_Date - 180 DAY AND current_Date;

Answer 1

This would be another way to do this
WITH CTE AS (
SELECT g.cust
, g.rep
FROM orders g
inner join dates i
on g.date1 = i.acyyyymmdd
WHERE
g.frm = $frm
AND g.cvr = $cvr
AND g.clr = $clr
)
SELECT
count(*) as sales_180Company
, 180/count(*) as velocityCompany
, 'cust' as query
FROM CTE
WHERE cust = $customer
UNION ALL
SELECT
count(*) as sales_180Company
, 180/count(*) as velocityCompany
, 'rep' as query
FROM CTE
WHERE rep = $rep
UNION ALL
SELECT
count(*) as sales_180Company
, 180/count(*) as velocityCompany
, 'all' as query
FROM CTE
which returns e.g.
SALES_180COMPANY VELOCITYCOMPANY QUERY
---------------- --------------- -----
3 60 cust
2 90 rep
5 36 all

Answer 2

select q1.*, q2.*, q3.*
from
(select count(*) as sales_180Cust, 180/count(*) as velocityCust from table(values 1) t(i)) q1
, (select count(*) as sales_180Rep, 180/count(*) as velocityRep from table(values 1, 2) t(i)) q2
, (select count(*) as sales_180Company, 180/count(*) as velocityCompany from table(values 1, 2, 3) t(i)) q3
I amended your FROM and WERE clauses to show the idea.

Answer 3

Lots of ways to do this. UNION would be an obvious way. GROUPING SETs is a bit more clever.
create table orders(date1 int, rep int, cust int,frm int, cvr int, clr int, aci int);
create table dates(acyyyymmdd int, aciso date);
create variable $frm int default 1;
create variable $cvr int default 1;
create variable $clr int default 1;
create variable $customer int default 1;
create variable $rep int default 1;
insert into orders values (1,0,0,1,1,1,1), (1,1,1,1,1,1,1), (1,2,1,1,1,1,1), (1,3,1,1,1,1,1), (1,1,2,1,1,1,1);
insert into dates values (1, current date);
then this
SELECT
count(*) as sales_180Company
, 180/count(*) as velocityCompany
, g.cust
, g.rep
FROM orders g
inner join dates i
on g.date1 = i.acyyyymmdd
WHERE
g.frm = $frm
AND g.cvr = $cvr
AND g.clr = $clr
AND i.aciso between current_Date - 180 DAY AND current_Date
GROUP BY GROUPING SETS ( (), (cust), (rep) )
HAVING (cust = $customer AND rep is null)
OR (cust is null AND rep = $rep)
OR (cust is null AND rep is null)
gives this
SALES_180COMPANY VELOCITYCOMPANY CUST REP
---------------- --------------- ---- ----
5 36 NULL NULL
3 60 1 NULL
2 90 NULL 1

Answer 4

Or this... there are often a multitude of ways to do things in SQL
WITH CTE AS (
SELECT g.cust
, g.rep
FROM orders g
inner join dates i
on g.date1 = i.acyyyymmdd
WHERE
g.frm = $frm
AND g.cvr = $cvr
AND g.clr = $clr
) , CUST AS (
SELECT
count(*) as sales_180Company
, 180/count(*) as velocityCompany
FROM CTE
WHERE cust = $customer
) , REP AS (
SELECT
count(*) as sales_180Company
, 180/count(*) as velocityCompany
FROM CTE
WHERE rep = $rep
) , ALL AS (
SELECT
count(*) as sales_180Company
, 180/count(*) as velocityCompany
FROM CTE
)
SELECT * FROM CUST, REP, ALL
retuning
SALES_180COMPANY VELOCITYCOMPANY SALES_180COMPANY VELOCITYCOMPANY SALES_180COMPANY VELOCITYCOMPANY
---------------- --------------- ---------------- --------------- ---------------- ---------------
3 60 2 90 5 36