Sorting a Result Set

3.16.1 Problem

Your query results aren't sorted the way you want.

3.16.2 Solution

MySQL can't read your mind. Add an ORDER BY clause to tell it exactly how you want things sorted.

3.16.3 Discussion

When you select rows, the MySQL server is free to return them in any order, unless you instruct it otherwise by saying how to sort the result. There are lots of ways to use sorting techniques. Chapter 6 explores this topic further. Briefly, you sort a result set by adding an ORDER BY clause that names the column or columns you want to sort by:

mysql> SELECT * FROM mail WHERE size > 100000 ORDER BY size;
+---------------------+---------+---------+---------+---------+---------+
| t | srcuser | srchost | dstuser | dsthost | size |
+---------------------+---------+---------+---------+---------+---------+
| 2001-05-12 12:48:13 | tricia | mars | gene | venus | 194925 |
| 2001-05-15 10:25:52 | gene | mars | tricia | saturn | 998532 |
| 2001-05-14 17:03:01 | tricia | saturn | phil | venus | 2394482 |
+---------------------+---------+---------+---------+---------+---------+
mysql> SELECT * FROM mail WHERE dstuser = 'tricia'
 -> ORDER BY srchost, srcuser;
+---------------------+---------+---------+---------+---------+--------+
| t | srcuser | srchost | dstuser | dsthost | size |
+---------------------+---------+---------+---------+---------+--------+
| 2001-05-15 10:25:52 | gene | mars | tricia | saturn | 998532 |
| 2001-05-14 11:52:17 | phil | mars | tricia | saturn | 5781 |
| 2001-05-17 12:49:23 | phil | mars | tricia | saturn | 873 |
| 2001-05-11 10:15:08 | barb | saturn | tricia | mars | 58274 |
| 2001-05-13 13:59:18 | barb | saturn | tricia | venus | 271 |
+---------------------+---------+---------+---------+---------+--------+

To sort a column in reverse (descending) order, add the keyword DESC after its name in the ORDER BY clause:

mysql> SELECT * FROM mail WHERE size > 50000 ORDER BY size DESC;
+---------------------+---------+---------+---------+---------+---------+
| t | srcuser | srchost | dstuser | dsthost | size |
+---------------------+---------+---------+---------+---------+---------+
| 2001-05-14 17:03:01 | tricia | saturn | phil | venus | 2394482 |
| 2001-05-15 10:25:52 | gene | mars | tricia | saturn | 998532 |
| 2001-05-12 12:48:13 | tricia | mars | gene | venus | 194925 |
| 2001-05-14 14:42:21 | barb | venus | barb | venus | 98151 |
| 2001-05-11 10:15:08 | barb | saturn | tricia | mars | 58274 |
+---------------------+---------+---------+---------+---------+---------+