How to return all records from table A , if any one of the column has a specific value in oracle sql? - sql

Question

Below is the sample data
If I pass lot name as a parameter, I want to return employees who has greater than 0 records in The specific Lot . Not just the one record but all the records of that employee.
Table A
Empid lotname itemcount
1 A 1
1 B 1
2 B 0
3 B 1
3 C 0
Parameter - B
Result :
Empid lotname itemcount
1 A 1
1 B 1
3 B 1
3 C 0
Because employee 3 and 1 has count in B lot. All the employee lot details should be returned.

Answer 1

select data.* from A data,
(select Empid,count(lotname)
from A
group by Empid
having count(lotname)>1) MulLotEmp
where data.lotname='B'
and data.Empid=MulLotEmp.Empid;
Check if this query solves your problem. In this I created a inner table first for your first requirement that emp with multiple lot, then I mapped this table with actual table with condition of input lot name.

Answer 2

If I understand correctly, you want all "1" and then only "0" if there is no "1".
One method is:
select a.*
from a
where itemcount = 1 or
not exists (select 1 from a a2 where a2.empid = a.empid and a2.itemcount = 1);

Answer 3

In Oracle, you can use the MAX analytic function:
SELECT Empid,
lotname,
itemcount
FROM (
SELECT t.*,
MAX( itemcount ) OVER ( PARTITION BY Empid ) AS max_itemcount
FROM table_name t
)
WHERE max_itemcount = 1;
So, for you sample data:
CREATE TABLE table_name ( Empid, lotname, itemcount ) AS
SELECT 1, 'A', 1 FROM DUAL UNION ALL
SELECT 1, 'B', 1 FROM DUAL UNION ALL
SELECT 2, 'B', 0 FROM DUAL UNION ALL
SELECT 3, 'B', 1 FROM DUAL UNION ALL
SELECT 3, 'C', 0 FROM DUAL;
This outputs:
EMPID | LOTNAME | ITEMCOUNT
----: | :------ | --------:
1 | A | 1
1 | B | 1
3 | B | 1
3 | C | 0
db<>fiddle here

Answer 4

The analytic function
sum(case when LOTNAME = 'B' /* parameter */ then ITEMCOUNT end) over (partition by EMPID) as lot_itemcnt
calculates for each customer the total number of items with the selected lot.
Feel free to use it as a bind variable, e.g.
sum(case when LOTNAME = ? /* parameter */ then ITEMCOUNT end) over (partition by EMPID) as lot_itemcnt
The whole query is than as follows
with cust as (
select
EMPID, LOTNAME, ITEMCOUNT,
sum(case when LOTNAME = 'B' /* parameter */ then ITEMCOUNT end) over (partition by EMPID) as lot_itemcnt
from tab)
select
EMPID, LOTNAME, ITEMCOUNT
from cust
where lot_itemcnt >= 1;