SQL Query to create a view with different grouping logic - mysql

Question

I have a table similar to below
Insurance ID
Created By
Closed By
1
User A
User A
2
User A
User C
3
User B
User C
4
User B
User C
5
User B
User C
From this table, I am trying to create a View as below
UserName
Total Created
Total Closed
User A
2
1
User B
3
0
User C
0
4
I am not able to figure out how to group the table to achieve this view. Any help would be greatly appreciated

Answer 1

Here's one option:
Sample data (you have it already, so you don't type that):
SQL> with test (insurance_id, created_by, closed_by) as
2 (select 1, 'user a', 'user a' from dual union all
3 select 2, 'user a', 'user c' from dual union all
4 select 3, 'user b', 'user c' from dual union all
5 select 4, 'user b', 'user c' from dual union all
6 select 5, 'user b', 'user c' from dual
7 ),
Query begins here:
8 all_users as
9 (select created_by username from test
10 union
11 select closed_by from test
12 )
13 select u.username,
14 sum(case when t.created_by = u.username then 1 else 0 end) total_created,
15 sum(case when t.closed_by = u.username then 1 else 0 end) total_closed
16 from all_users u cross join test t
17 group by u.username
18 order by u.username;
USERNA TOTAL_CREATED TOTAL_CLOSED
------ ------------- ------------
user a 2 1
user b 3 0
user c 0 4
SQL>

Answer 2

I would be inclined to have a separate Users table and only have an integer of UserId in the main table. CROSS APPLY should avoid reading the same table twice.
SELECT X.UserName
,SUM(CASE WHEN X.Activity = 'Created' THEN 1 ELSE 0 END) AS TotalCreated
,SUM(CASE WHEN X.Activity = 'Closed' THEN 1 ELSE 0 END) AS TotalClosed
FROM YourTable T
CROSS APPLY
(
VALUES (T.CreatedBy, 'Created')
,(T.ClosedBy, 'Closed')
) X (UserName, Activity)
GROUP BY X.UserName
ORDER BY UserName;

Answer 3

create table sometable (user_id, created_by,closed_by)
as
select 1, 'user a', 'user a' from dual union all
select 2, 'user a', 'user c' from dual union all
select 3, 'user b', 'user c' from dual union all
select 4, 'user b', 'user c' from dual union all
select 5, 'user b', 'user c' from dual;
SELECT *
FROM sometable
UNPIVOT ( username
FOR col IN ( created_by
, closed_by
)
)
PIVOT ( COUNT (user_id)
FOR col IN ( 'CREATED_BY' AS total_created
, 'CLOSED_BY' AS total_closed
)
)
ORDER BY username
;
USERNAME TOTAL_CREATED TOTAL_CLOSED
user a 2 1
user b 3 0
user c 0 4