How to use count using case statements

Question

I am trying to get the total number of items and categorize them using case statements. However, I keep getting the items (which are now categorized as "inv") repeated (eg "clothes" is repeated 4 times, each with a count of 1 instead of just once with the total count of 4) - how do I get rid of that? I included the desired outcome below.

Here's my table:

TABLE BOX1

ITEM_NO ITEM             DATE
===================================
3130C   MARVEL_SHIRT     01-JAN-17
1845C   SPONGEBOB_BOXERS 03-DEC-18
A900C   CK_COAT          04-DEC-18
A988C   RIDER_JEANS      11-JAN-19
L350T   BARBIE           23-NOV-18
L129T   LEGO             09-OCT-18
LXZYT   BATMAN_FIG1      12-JAN-19

My code:

select (case substr (item_no,5,1)
    when 'C' then 'clothes'
    when 'T' then 'toys' else 'misc' end) inv, 
    count(item_no) total 
from box1 where date <= sysdate
    group by item

Desired Outcome:

INV     TOTAL
===============
CLOTHES 4
TOYS    3

Answer 1

You need to group by your categories.

SELECT CASE substr(item_no, 5, 1)
         WHEN 'C' THEN
           'clothes'
         WHEN 'T' THEN
           'toys'
         ELSE
           'misc'
       END inv, 
       count(item_no) total 
       FROM box1
       WHERE date <= sysdate
       GROUP BY CASE substr(item_no, 5, 1)
                  WHEN 'C' THEN
                    'clothes'
                  WHEN 'T' THEN
                    'toys'
                  ELSE
                    'misc'
                END;

Answer 2

Becasue of the nature of your expression, you only need to aggregate on substr() :

select (case substr(item_no, 5, 1)
            when 'C' then 'clothes'
            when 'T' then 'toys'
            else 'misc' 
        end) inv, 
       count(item_no) total 
from box1
where date <= sysdate
group by substr(item_no, 5, 1);