RE: Get COUNT results from two different columns

Greetings,

I have two separate queries that work individually, returning a count from
each column.

I want to subtract New(COUNT) from Old(Count)

I get an error when trying to run UNION?

I would appreciate any pointers.

-- COUNT NEW SUPPLIER

--

SELECT new_sup,

COUNT(new_sup)

FROM public."Data"

GROUP BY new_sup

This returns

Company_D 35

Company_E 30

Company_F 30

SELECT newld_sup,

COUNT(old_sup)

FROM public."Data"

GROUP BY old_sup

This returns

Company_A 1

Company_B 2

Company_D 35

Company_E 30

Company_F 30

SELECT new_sup, COUNT(new_sup) AS new_sup_count,

old_sup, COUNT(old_sup) AS old_sup_count

FROM

(

SELECT

new_sup, COUNT(new_sup) AS new_sup_count

FROM public."Data"

GROUP BY new_sup

UNION

SELECT

old_sup, COUNT(old_sup) AS old_sup_count

FROM public."Data"

GROUP BY old_sup

new_sup_count - old_sup_count

)

GROUP BY new_sup