Hi,
I have the following data:
mysql> select obs_id, obs_URI, obs_source, beg_date from observation;
+--------+------------------------------------+------------+------------+
| obs_id | obs_URI | obs_source | beg_date |
+--------+------------------------------------+------------+------------+
| 4 | URIRAC://landsat-7/19990419/120850 | landsat-7 | 1999-04-19 |
| 3 | URIRAC://landsat-7/19990519/90850 | landsat-7 | 1999-05-19 |
| 2 | URIRAC://landsat-7/19990519/90850 | GOES-J | 1999-05-19 |
| 1 | URIRAC://noaa-14/19990124/90850 | noaa-14 | 1999-01-24 |
| 5 | URIRAC://landsat-7/19990419/120850 | landsat-7 | 1999-04-19 |
| 6 | URIRAC://goes-j/19990202/111250 | goes-j | 1999-02-02 |
+--------+------------------------------------+------------+------------+
6 rows in set (0.01 sec)
I do
mysql> select obs_id, obs_URI, obs_source, beg_date from observation where
beg_date = '19990519';
+--------+-----------------------------------+------------+------------+
| obs_id | obs_URI | obs_source | beg_date |
+--------+-----------------------------------+------------+------------+
| 3 | URIRAC://landsat-7/19990519/90850 | landsat-7 | 1999-05-19 |
| 2 | URIRAC://landsat-7/19990519/90850 | GOES-J | 1999-05-19 |
+--------+-----------------------------------+------------+------------+
2 rows in set (0.01 sec)
and
mysql> select obs_id, obs_URI, obs_source, beg_date, beg_time from
observation where beg_date between '1999-01-20' and '1999-05-30';
+--------+------------------------------------+------------+------------+----------+
| obs_id | obs_URI | obs_source | beg_date |
beg_time |
+--------+------------------------------------+------------+------------+----------+
| 4 | URIRAC://landsat-7/19990419/120850 | landsat-7 | 1999-04-19 |
12:08:50 |
| 3 | URIRAC://landsat-7/19990519/90850 | landsat-7 | 1999-05-19 |
09:08:50 |
| 2 | URIRAC://landsat-7/19990519/90850 | GOES-J | 1999-05-19 |
09:08:50 |
| 1 | URIRAC://noaa-14/19990124/90850 | noaa-14 | 1999-01-24 |
09:08:50 |
| 5 | URIRAC://landsat-7/19990419/120850 | landsat-7 | 1999-04-19 |
12:08:50 |
| 6 | URIRAC://goes-j/19990202/111250 | goes-j | 1999-02-02 |
11:12:50 |
+--------+------------------------------------+------------+------------+----------+
6 rows in set (0.01 sec)
but the following sql command does not seem to work as I expected it to:
mysql> select obs_id, obs_URI, obs_source, beg_date, beg_time from
observation where beg_date between '19990124' and '19990519';
Empty set (0.01 sec)
or
mysql> select obs_id, obs_URI, obs_source, beg_date, beg_time from
observation where beg_date between '19990120' and '19990530';
Empty set (0.01 sec)
Could any one explain this to me, please?
---
Claudia M. Castaneda
KT-Tech, Incorporated
9801 Greenbelt Rd. Suite 314
Lanham MD 20706 USA
301 552 2411 Fax 301 552 2638
