Database Reference
In-Depth Information
interesting sender might be
postmaster
or
root
. Those names don't appear in the table,
so let's use
phil
as the name of interest instead:
mysql>
SELECT t, srcuser, dstuser, size
->
FROM mail
->
ORDER BY IF(srcuser='phil',0,1), srcuser, dstuser;
+---------------------+---------+---------+---------+
| t | srcuser | dstuser | size |
+---------------------+---------+---------+---------+
| 2014-05-16 23:04:19 | phil | barb | 10294 |
| 2014-05-12 15:02:49 | phil | phil | 1048 |
| 2014-05-15 08:50:57 | phil | phil | 978 |
| 2014-05-14 11:52:17 | phil | tricia | 5781 |
| 2014-05-19 12:49:23 | phil | tricia | 873 |
| 2014-05-14 14:42:21 | barb | barb | 98151 |
| 2014-05-11 10:15:08 | barb | tricia | 58274 |
| 2014-05-12 18:59:18 | barb | tricia | 271 |
| 2014-05-14 09:31:37 | gene | barb | 2291 |
| 2014-05-16 09:00:28 | gene | barb | 613 |
| 2014-05-15 17:35:31 | gene | gene | 3856 |
| 2014-05-15 07:17:48 | gene | gene | 3824 |
| 2014-05-19 22:21:51 | gene | gene | 23992 |
| 2014-05-15 10:25:52 | gene | tricia | 998532 |
| 2014-05-12 12:48:13 | tricia | gene | 194925 |
| 2014-05-14 17:03:01 | tricia | phil | 2394482 |
+---------------------+---------+---------+---------+
The value of the extra sort column is
0
for rows in which the
srcuser
value is
phil
, and
1
for all other rows. By making that the most significant sort column, rows for messages
sent by
phil
float to the top of the output. (To sink them to the bottom instead, either
sort the column in reverse order using
DESC
, or reverse the order of the second and third
arguments of the
IF()
function.)
You can also use this technique for particular conditions, not only specific values. To
put first those rows where people sent messages to themselves, do this:
mysql>
SELECT t, srcuser, dstuser, size
->
FROM mail
->
ORDER BY IF(srcuser=dstuser,0,1), srcuser, dstuser;
+---------------------+---------+---------+---------+
| t | srcuser | dstuser | size |
+---------------------+---------+---------+---------+
| 2014-05-14 14:42:21 | barb | barb | 98151 |
| 2014-05-19 22:21:51 | gene | gene | 23992 |
| 2014-05-15 17:35:31 | gene | gene | 3856 |
| 2014-05-15 07:17:48 | gene | gene | 3824 |
| 2014-05-12 15:02:49 | phil | phil | 1048 |
| 2014-05-15 08:50:57 | phil | phil | 978 |
| 2014-05-11 10:15:08 | barb | tricia | 58274 |
| 2014-05-12 18:59:18 | barb | tricia | 271 |
| 2014-05-16 09:00:28 | gene | barb | 613 |
| 2014-05-14 09:31:37 | gene | barb | 2291 |
