HAVING COUNT() not giving out the expected result - sql

Question

Attempting to get duplicate values of produce.prod_id using distinct, having clauses.but not giving out the expected result.
Here's my data:
PRODUCE
--------- -----------
PROD_ID PROD_NAME
--------- -----------
1 APPLES
2 PEARS
3 ORANGES
4 BANANAS
5 PEACHES
BUYERS
---------- ------------
BUYER_ID BUYER_NAME
---------- --------------
1 ADAM BARR
2 SEAN CHAI
3 EVA CORETS
4 ERIN O`MELIA
SALES
---------- --------- ------
BUYER_ID PROD_ID QTY
---------- --------- ------
1 2 15
1 3 5
4 1 37
3 5 11
4 3 1005
and here's my code:
select produce.prod_name,
buyer.BUYER_NAME,
SALES.PROD_ID
from produce
inner join SALES on produce.PROD_ID = SALES.PROD_ID
inner join buyer on SALES.BUYER_ID = buyer.BUYER_ID
group by produce.prod_name,
buyer.BUYER_NAME,
SALES.PROD_ID
having count(SALES.PROD_ID) > 1;
Expected result:
PROD_Name Buyer_Name
----------- --------------
Oranges ADAM BARR
Oranges ERIN O`MELIA

Answer 1

You need to use analytical function for your requirement
WITH PRODUCE(PROD_ID, PROD_NAME) AS (
SELECT 1, 'APPLES' from dual union all
select 2, 'PEARS' from dual union all
select 3, 'ORANGES' from dual union all
select 4, 'BANANAS' from dual union all
select 5, 'PEACHES' from dual),
BUYERS (BUYER_ID, BUYER_NAME) as (
select 1, 'ADAM BARR' from dual union all
select 2, 'SEAN CHAI' from dual union all
select 3, 'EVA CORETS' from dual union all
select 4, 'ERIN O`MELIA' from dual),
SALES(BUYER_ID, PROD_ID, QTY) as (
select 1, 2, 15 from dual union all
select 1, 3, 5 from dual union all
select 4, 1, 37 from dual union all
select 3, 5, 11 from dual union all
select 4, 3, 1005 from dual),
-- End of data preparation
TABLE_ AS (
SELECT produce.prod_name,
buyers.buyer_name,
sales.prod_id,
COUNT(1) OVER (PARTITION BY sales.prod_id) p_count
FROM produce
INNER JOIN sales
ON produce.prod_id = sales.prod_id
INNER JOIN buyers
ON sales.buyer_id = buyers.buyer_id)
SELECT prod_name, buyer_name, prod_id
FROM table_
WHERE p_count > 1;
Output:
| PROD_NAME | BUYER_NAME | PROD_ID |
|-----------|--------------|---------|
| ORANGES | ERIN O`MELIA | 3 |
| ORANGES | ADAM BARR | 3 |
Update: You simplified query would be:
With TABLE_ AS (
SELECT produce.prod_name,
buyers.buyer_name,
sales.prod_id,
COUNT(1) OVER (PARTITION BY sales.prod_id) p_count
FROM produce
INNER JOIN sales
ON produce.prod_id = sales.prod_id
INNER JOIN buyers
ON sales.buyer_id = buyers.buyer_id)
SELECT prod_name, buyer_name, prod_id
FROM table_
WHERE p_count > 1;

Answer 2

you don't need distinct. you only need group by and having. you also cant group by buyer_name to get a count > 1. that is where the issue lies, you can to do this as a set of nested queries
select dupes.prod_name,
buyers.buyer_name
from (
select produce.prod_name,
SALES.PROD_ID,
count(SALES.PROD_ID)
from produce
inner join SALES on produce.PROD_ID=SALES.PROD_ID
group by produce.prod_name,
SALES.PROD_ID
having count(*)>1
) as dupes
inner join sales on sales.prod_id = dupes.prod_id
inner join buyers on buyers.buyer_id = sales.buyer_id

Answer 3

Here's my, hopefully, simple answer.
Here's my SQL Fiddle scratch pad as well. http://sqlfiddle.com/#!9/d80f6/3
select P.Prod_Name, Buyer_Name
from Sales S
join
(select prod_id, count(prod_id) as ActSales
from Sales group by prod_id having count(prod_id) > 1) SQ
on S.Prod_Id = SQ.Prod_Id
join Produce P
on S.Prod_Id = P.Prod_Id
join Buyers B
on S.Buyer_Id = B.Buyer_Id