Hi,
I was looking for a simple solution to this problem. I can't find a way
to group on b and n by just collapsing sequential n's (identical n's
right next to each other) the sorting condition is the timestamp.
b | n | stamp
----------------------------------------A | 1 | 2008-09-20 06:07:47.981445A | 1 | 2008-09-20 06:08:13.294306A
| 1 | 2008-09-20 06:12:02.046596A | 2 | 2008-09-20 06:12:26.267786A | 2 | 2008-09-20 06:12:47.750429A | 1
|2008-09-20 06:13:12.152512A | 2 | 2008-09-20 06:13:39.052528A | 2 | 2008-09-20 06:14:12.875389B | 1 |
2008-09-2006:14:29.963352B | 1 | 2008-09-20 06:14:52.247307B | 3 | 2008-09-20 06:15:13.358151B | 3 |
2008-09-2006:15:44.307792B | 3 | 2008-09-20 06:16:17.32131B | 2 | 2008-09-20 06:16:44.030435B | 2 |
2008-09-2006:17:00.140907C | 1 | 2008-09-20 06:17:50.067258C | 1 | 2008-09-20 06:18:22.280218C | 1 |
2008-09-2006:18:41.661213C | 1 | 2008-09-20 06:19:07.920327C | 3 | 2008-09-20 06:19:26.166675C | 2 |
2008-09-2006:19:46.459439C | 2 | 2008-09-20 06:20:04.634328
Here I give an example of the output I'm looking for, And I can find a
way to do that in crystal report, but I would like postgresql to send it
that way. If the next n is different create a new row.
b | n | min_stamp | max_stamp
--------------------------------------------------------------------- A | 1 | 2008-09-20 06:07:47.981445 |
2008-09-2006:12:02.046596 A | 2 | 2008-09-20 06:12:26.267786 | 2008-09-20 06:12:47.750429 A | 1 | 2008-09-20
06:13:12.152512| 2008-09-20 06:13:12.152512 A | 2 | 2008-09-20 06:13:39.052528 | 2008-09-20 06:14:12.875389 B |
1 | 2008-09-20 06:14:29.963352 | 2008-09-20 06:14:52.247307 B | 3 | 2008-09-20 06:15:13.358151 | 2008-09-20
06:16:17.32131B | 2 | 2008-09-20 06:16:44.030435 | 2008-09-20 06:17:00.140907 C | 1 | 2008-09-20
06:17:50.067258| 2008-09-20 06:19:07.920327 C | 3 | 2008-09-20 06:19:26.166675 | 2008-09-20 06:19:26.166675 C |
2 | 2008-09-20 06:19:46.459439 | 2008-09-20 06:20:04.634328
If I write a GROUP BY b,n there is going to be only two rows for b =
'A', if I use distinct on i get the same thing
is there an easy way to do that ?
Nicolas
