MYSQL: How can I find 'last monday's date' (performance Issue)

Question

is there a simpler way than writing:

select date_sub(curdate(), interval WEEKDAY(curdate()) day) as LastMonday
from dual

Answer 1

If you're not using an ancient MySQL, you can wrap this in a stored function.

CREATE FUNCTION `LastMonday`() RETURNS DATETIME    
  RETURN DATE_SUB(CURDATE(), INTERVAL WEEKDAY(CURDATE()) DAY) ;

and then call

select LastMonday() as LastMonday

Update:

If you're having performance problems, you can persist the value in a session variable. That way you can be sure that it will only be calculated once.

set @LastMonday=LastMonday();
select @Lastmonday; 

(in this simple query it makes no difference of course...)