Question

I have a column c in table tbl which contains the following values.

Tue, 15 Nov 2011 14:21:32 GMT
Tue, 15 Nov 2011 12:59:21 GMT
Tue, 15 Nov 2011 12:15:48 GMT
Tue, 15 Nov 2011 12:10:33 GMT
Tue, 15 Nov 2011 11:12:09 GMT
Tue, 15 Nov 2011 11:09:14 GMT
Tue, 15 Nov 2011 10:38:01 GMT
Tue, 15 Nov 2011 10:36:33 GMT
Tue, 15 Nov 2011 10:09:21 GMT
Tue, 15 Nov 2011 09:23:01 GMT
Tue, 15 Nov 2011 08:24:39 GMT
Mon, 14 Nov 2011 22:44:53 GMT
Mon, 14 Nov 2011 21:03:28 GMT
Mon, 14 Nov 2011 20:12:11 GMT
Mon, 14 Nov 2011 19:08:34 GMT
Mon, 14 Nov 2011 18:40:05 GMT
Mon, 14 Nov 2011 18:07:00 GMT
Mon, 14 Nov 2011 18:04:00 GMT
Mon, 14 Nov 2011 17:37:45 GMT

These values were taken from command:

select c from tbl;

When I run:

select count(*) from tbl where c < date('2011-11-18');

the result is 0

What is wrong here?

thank you

Answer 1

What you have stored in your database are regular strings, not SQLite datetime strings.

For the contents to TEXT column to be recognized as a datetime it must be stored in the format YYYY-MM-DD HH:MM:SS.SSS.

To get the results you want out of the data you have, you will have to use string comparisons, and doing the < comparison that you want will be tricky (you’ll need to examine substrings and look for year < 2011 OR month IN (JAN,FEB,MAR. . .) OR (month = 'NOV' AND day < 18).

Better to:

1. Find where the data is inserted and change it to insert a “proper” SQLite date and

2. Run a one-time routine over the existing data to reformat it.