Trouble with date ranges - mysql

Question

I need to check for entries made in the last "x" days (example 30 days) and cannot get the query to work. This is what I am using:
SELECT CAL_OWNER,
CAL_TITLE,
FROM_UNIXTIME (CAL_CREATED, "%m-%d-%y") AS CREATED,
FROM_UNIXTIME (RANGE_START, "%Y-%m-%d") AS DATE2BESEEN,
CASE CAL_REFERRAL_TYPE
WHEN 1 THEN 'NoReferral'
WHEN 2 THEN 'CareyGuide'
WHEN 3 THEN 'Education'
WHEN 4 THEN 'Employment'
WHEN 5 THEN 'Housing'
WHEN 6 THEN 'Medical'
ELSE 'NA'
END
AS REFERRALS
FROM EGW_CAL
WHERE CAL_CREATED BETWEEN (NOW () - '30 day') AND NOW ()
ORDER BY REFERRALS ASC;
If I comment out the "WHERE range_start ... line the query runs fine, but pulls all data
However, if I run the complete query, it does not error, but there are no results (I have 4 entries in column cal_created in the last 3 weeks).
If some one can help I'd really appreciate it

Answer 1

Try using INTERVAL and either NOW() or CURDATE()..
WHERE FROM_UNIXTIME (CAL_CREATED,'%Y-%m-%d') BETWEEN CURDATE() - INTERVAL 30 DAY AND CURDATE()
curdate is just the date portion of the day
if you want to include the time use NOW()
WHERE FROM_UNIXTIME (CAL_CREATED,'%Y-%m-%d') BETWEEN NOW() - INTERVAL 30 DAY AND NOW()
you could also make a new date to use the between with
WHERE FROM_UNIXTIME (CAL_CREATED,'%Y-%m-%d') BETWEEN DATE_SUB(NOW(), INTERVAL 30 DAY) AND NOW()
SOURCE: http://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html
NOTE: the dates need to be formatted correctly in order for it to work
FULL QUERY:
SELECT
CAL_OWNER,
CAL_TITLE,
FROM_UNIXTIME (CAL_CREATED, '%m-%d-%y') AS CREATED_AT,
FROM_UNIXTIME (RANGE_START, '%Y-%m-%d') AS DATE2BESEEN,
CASE CAL_REFERRAL_TYPE
WHEN 1 THEN 'NoReferral'
WHEN 2 THEN 'CareyGuide'
WHEN 3 THEN 'Education'
WHEN 4 THEN 'Employment'
WHEN 5 THEN 'Housing'
WHEN 6 THEN 'Medical'
ELSE 'NA'
END AS REFERRALS
FROM EGW_CAL
WHERE FROM_UNIXTIME(CAL_CREATED,'%Y-%m-%d') BETWEEN (NOW() - INTERVAL 30 DAY) AND NOW()
ORDER BY REFERRALS ASC;

Answer 2

CAL_CREATED is a UNIX timestamp,
NOW() will return a MySQL timestamp.
They don't mix automatically. So use
WHERE CAL_CREATED
BETWEEN UNIX_TIMESTAMP(NOW() - INTERVAL 30 DAY) AND UNIX_TIMESTAMP(NOW());
Note:
I wouldn't recommend to go the other way
WHERE FROM_UNIXTIME(CAL_CREATED) BETWEEN ...
because MySQL can't use an index in this case.

Answer 3

The correct where clause uses internval:
WHERE CAL_CREATED BETWEEN NOW() - interval 30 day AND NOW()
The use of single quotes is reminiscent of Postgres. In MySQL, it ends up treating the value of now() as an integer. And it subtracts the string value "30 days" from it.
When now() is treated as an integer, it also has hours, minutes, and seconds. So you are really subtracting something like 30 seconds. Here is the documentation on now().