checking if a date falls in given date range using mysql query

Question

I have these two columns in my database table 'mycodes'

code_valid_from_date
code_expiry_date

I need to check if a given date falls in valid period of the dates given in mycodes tables.

For example,

mycodes
id, code_valid_from_date, code_expiry_date, name
1, 2013-08-01, 2013-08-28, 'Code 1'
2, 2013-08-29, 2013-09-20, 'Code 2'
3, 2013-07-01, 2013-07-28, 'Code 3'

I tried this query,

SELECT
DATEDIFF(NOW(), code_valid_from_date) valid_from_days, 
DATEDIFF(code_expiry_date, NOW()) expiry_days_left
FROM mycodes

then in my php code I check both of these DATEDIFF are positive numbers then its a valid code. What if I have to compute this validity in the mysql query itself rather than checking using PHP? How do I do that?

PS: I could also use a BETWEEN in WHERE clause but that will return rows which fall in that given range but I need to list all the records with status of expired or not expired.

Answer 1

Mysql知道可以比较日期，因此您可以使用类似以下的内容：

SELECT (NOW() >= code_valid_from_date AND NOW() <= code_expiry_date) AS valid FROM mycodes

Answer 2

选择（NOW（）在code_valid_from_date和code_expiry_date之间）作为有效自mycodes

Answer 3

This is my code to find if a date range falls within another date range. I'm sure you could modify my choosing the same date as your arrival and departure date.

Example that works for me and my queries:

SET @PerBeg = ’2010-01-01’;
  SET @PerEnd = ’2010-01-31’;

  SELECT  
      Reservation.ArrivalDate AS ArrivalDate, 
      Reservation.DepartureDate AS DepartureDate, 
  . . . 

  WHERE

  fBoolActyInPeriod(ArrivalDate,DepartureDate,@PerBeg,@PerEnd)

using these functions

  FUNCTION fBoolActyInPeriod contains this code
  RETURN IF (fBoolFirstDateEarlier(ActyEnd, PerBeg) OR fBoolFirstDateEarlier(PerEnd, ActyBeg),0, 1)

  FUNCTION fBoolFirstDateEarlier contains this code
  RETURN IF (DATEDIFF(first, second) < 0, 1, 0)