Is it possible to fetch needed data in one query? - mysql

Question

I have a database containing tickets. Each ticket has a unique number but this number is not unique in the table. So for example ticket #1000 can be multiple times in the table with different other columns (Which I have removed here for the example).
create table countries
(
isoalpha varchar(2),
pole varchar(50)
);
insert into countries values ('DE', 'EMEA'),('FR', 'EMEA'),('IT', 'EMEA'),('US','USCAN'),('CA', 'USCAN');
create table tickets
(
id int primary key auto_increment,
number int,
isoalpha varchar(2),
created datetime
);
insert into tickets (number, isoalpha, created) values
(1000, 'DE', '2021-01-01 00:00:00'),
(1001, 'US', '2021-01-01 00:00:00'),
(1002, 'FR', '2021-01-01 00:00:00'),
(1003, 'CA', '2021-01-01 00:00:00'),
(1000, 'DE', '2021-01-01 00:00:00'),
(1000, 'DE', '2021-01-01 00:00:00'),
(1004, 'DE', '2021-01-02 00:00:00'),
(1001, 'US', '2021-01-01 00:00:00'),
(1002, 'FR', '2021-01-01 00:00:00'),
(1005, 'IT', '2021-01-02 00:00:00'),
(1006, 'US', '2021-01-02 00:00:00'),
(1007, 'DE', '2021-01-02 00:00:00');
Here is an example:
http://sqlfiddle.com/#!9/3f4ba4/6
What I need as output is the number of new created tickets for each day, devided into tickets from USCAN and rest of world.
So for this Example the out coming data should be
Date | USCAN | Other
'2021-01-01' | 2 | 2
'2021-01-02' | 1 | 3
At the moment I use this two queries to fetch all new tickets and then add the number of rows with same date in my application code:
SELECT MIN(ti.created) AS date
FROM tickets ti
LEFT JOIN countries ct ON (ct.isoalpha = ti.isoalpha)
WHERE ct.pole = 'USCAN'
GROUP BY ti.number
ORDER BY date
SELECT MIN(ti.created) AS date
FROM tickets ti
LEFT JOIN countries ct ON (ct.isoalpha = ti.isoalpha)
WHERE ct.pole <> 'USCAN'
GROUP BY ti.number
ORDER BY date
but that doesn't look like a very clean method. So how can I improved the query to get the needed data with less overhead?
Ii is recommended that is works with mySQL 5.7

Answer 1

You may logically combine the queries using conditional aggregation:
SELECT
MIN(CASE WHEN ct.pole = 'USCAN' THEN ti.created END) AS date_uscan,
MIN(CASE WHEN ct.pole <> 'USCAN' THEN ti.created END) AS date_other
FROM tickets ti
LEFT JOIN countries ct ON ct.isoalpha = ti.isoalpha
GROUP BY ti.number
ORDER BY date;

Answer 2

You can create unique entries for each date/country then use that value to count USCAN and non-USCAN
SELECT created,
SUM(1) as total,
SUM(CASE WHEN pole = 'USCAN' THEN 1 ELSE 0 END) as uscan,
SUM(CASE WHEN pole != 'USCAN' THEN 1 ELSE 0 END) as nonuscan
FROM (
SELECT created, t.isoalpha, MIN(pole) AS pole
FROM tickets t JOIN countries c ON t.isoalpha = c.isoalpha
GROUP BY created,isoalpha
) AS uniqueTickets
GROUP BY created
Results:
created total uscan nonuscan
2021-01-01T00:00:00Z 4 2 2
2021-01-02T00:00:00Z 3 1 2
http://sqlfiddle.com/#!9/3f4ba4/45/0

Answer 3

Regarding the answer of SQL Hacks I found the right solution
SELECT created,
SUM(1) as total,
SUM(CASE WHEN pole = 'USCAN' THEN 1 ELSE 0 END) as uscan,
SUM(CASE WHEN pole != 'USCAN' THEN 1 ELSE 0 END) as nonuscan
FROM (
SELECT created, t.isoalpha, MIN(pole) AS pole
FROM tickets t JOIN countries c ON t.isoalpha = c.isoalpha
GROUP BY t.number
) AS uniqueTickets
GROUP BY SUBSTR(created, 1 10)