mysql从同一个表中的另一列更新值

Question

I have a table with these 2 columns : date and day date has dates and day is empty I would like to do something like this :

UPDATE table SET day='day(date)' 

the idea is to take the date (its in date time format) and take out the day and insert it into the day column. any ideas ?

Answer 1

Hope this will help

UPDATE table SET day = EXTRACT(DAY FROM date)