MySQL 8.0

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create table sales_data (id int, udf varchar(20), date_of_sale datetime);
insert into sales_data values (1, 'alfa bravo', '2023-03-08 12:13:30');
select * from sales_data;


id
udf
date_of_sale


1
alfa bravo
2023-03-08 12:13:30


alter table sales_data add weekday varchar(10) GENERATED ALWAYS
  AS (CASE   
    WHEN weekday(subtime(s.date_of_sale ,'6:0:0'))=0 THEN 'Sunday'  
    WHEN weekday(subtime(s.date_of_sale ,'6:0:0'))=1 THEN 'Monday'  
    WHEN weekday(subtime(s.date_of_sale ,'6:0:0'))=2 THEN 'Tuesday'  
    WHEN weekday(subtime(s.date_of_sale ,'6:0:0'))=3 THEN 'Wednesday'  
    WHEN weekday(subtime(s.date_of_sale ,'6:0:0'))=4 THEN 'Thursday'  
    WHEN weekday(subtime(s.date_of_sale ,'6:0:0'))=5 THEN 'Friday'  
    WHEN weekday(subtime(s.date_of_sale ,'6:0:0'))=6 THEN 'Saturday'  
END );

Records: 0  Duplicates: 0  Warnings: 0


insert into sales_data (id, udf, date_of_sale)
  values (2, 'charlie delta', '2023-03-09 10:23:00');
select * from sales_data;


id
udf
date_of_sale
weekday


1
alfa bravo
2023-03-08 12:13:30
Tuesday

2
charlie delta
2023-03-09 10:23:00
Wednesday

id	udf	date_of_sale	weekday
1	alfa bravo	2023-03-08 12:13:30	Tuesday
2	charlie delta	2023-03-09 10:23:00	Wednesday