MySQL 8.0

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CREATE TABLE sales
( id            INT    ( 10) UNSIGNED AUTO_INCREMENT PRIMARY KEY,
  event_name    VARCHAR( 99),
  cashier_name  VARCHAR( 99),
  sale_date     VARCHAR( 99),
  sale_time     VARCHAR( 99)
) ENGINE=INNODB;


INSERT INTO sales (id, event_name, cashier_name, sale_date, sale_time)
           VALUES (1, 'Metallico 8pm',   'Jenny', '2022-03-11', '15:37'),
                  (2, 'Metallico 8pm',   'Sandy', '2022-03-11', '16:01'),
                  (3, 'Red Puppets 10am','Jenny', '2022-03-08', '09:40'),
                  (4, 'Red Puppets 10am','Jenny', '2022-03-11', '08:55'),
                  (5, 'Wild Cats 8pm',   'Sandy', '2022-02-25', '19:13'),
                  (6, 'Wild Cats 8pm',   'Jenny', '2022-02-25', '16:59');
select * from sales;


id
event_name
cashier_name
sale_date
sale_time


1
Metallico 8pm
Jenny
2022-03-11
15:37

2
Metallico 8pm
Sandy
2022-03-11
16:01

3
Red Puppets 10am
Jenny
2022-03-08
09:40

4
Red Puppets 10am
Jenny
2022-03-11
08:55

5
Wild Cats 8pm
Sandy
2022-02-25
19:13

6
Wild Cats 8pm
Jenny
2022-02-25
16:59


select CASHIER_NAME
from sales
group by cashier_name,sale_date
having COUNT( distinct event_name) >1 ;


CASHIER_NAME


Jenny

id	event_name	cashier_name	sale_date	sale_time
1	Metallico 8pm	Jenny	2022-03-11	15:37
2	Metallico 8pm	Sandy	2022-03-11	16:01
3	Red Puppets 10am	Jenny	2022-03-08	09:40
4	Red Puppets 10am	Jenny	2022-03-11	08:55
5	Wild Cats 8pm	Sandy	2022-02-25	19:13
6	Wild Cats 8pm	Jenny	2022-02-25	16:59