Introduction

This chapter covers sorting, an operation that is extremely important for controlling how MySQL displays results from SELECT statements. Sorting is performed by adding an ORDER BY clause to a query. Without such a clause, MySQL is free to return rows in any order, so sorting helps bring order to disorder and make query results easier to examine and understand. (Sorting also is performed implicitly when you use a GROUP BY clause, as discussed in Recipe 7.14.)

One of the tables used for quite a few examples in this chapter is driver_log, a table that contains columns for recording daily mileage logs for a set of truck drivers:

mysql> SELECT * FROM driver_log;
+--------+-------+------------+-------+
| rec_id | name | trav_date | miles |
+--------+-------+------------+-------+
| 1 | Ben | 2001-11-30 | 152 |
| 2 | Suzi | 2001-11-29 | 391 |
| 3 | Henry | 2001-11-29 | 300 |
| 4 | Henry | 2001-11-27 | 96 |
| 5 | Ben | 2001-11-29 | 131 |
| 6 | Henry | 2001-11-26 | 115 |
| 7 | Suzi | 2001-12-02 | 502 |
| 8 | Henry | 2001-12-01 | 197 |
| 9 | Ben | 2001-12-02 | 79 |
| 10 | Henry | 2001-11-30 | 203 |
+--------+-------+------------+-------+

Many other examples use the mail table (first seen in earlier chapters):

mysql> SELECT * FROM mail;
+---------------------+---------+---------+---------+---------+---------+
| t | srcuser | srchost | dstuser | dsthost | size |
+---------------------+---------+---------+---------+---------+---------+
| 2001-05-11 10:15:08 | barb | saturn | tricia | mars | 58274 |
| 2001-05-12 12:48:13 | tricia | mars | gene | venus | 194925 |
| 2001-05-12 15:02:49 | phil | mars | phil | saturn | 1048 |
| 2001-05-13 13:59:18 | barb | saturn | tricia | venus | 271 |
| 2001-05-14 09:31:37 | gene | venus | barb | mars | 2291 |
| 2001-05-14 11:52:17 | phil | mars | tricia | saturn | 5781 |
| 2001-05-14 14:42:21 | barb | venus | barb | venus | 98151 |
| 2001-05-14 17:03:01 | tricia | saturn | phil | venus | 2394482 |
| 2001-05-15 07:17:48 | gene | mars | gene | saturn | 3824 |
| 2001-05-15 08:50:57 | phil | venus | phil | venus | 978 |
| 2001-05-15 10:25:52 | gene | mars | tricia | saturn | 998532 |
| 2001-05-15 17:35:31 | gene | saturn | gene | mars | 3856 |
| 2001-05-16 09:00:28 | gene | venus | barb | mars | 613 |
| 2001-05-16 23:04:19 | phil | venus | barb | venus | 10294 |
| 2001-05-17 12:49:23 | phil | mars | tricia | saturn | 873 |
| 2001-05-19 22:21:51 | gene | saturn | gene | venus | 23992 |
+---------------------+---------+---------+---------+---------+---------+

Other tables are used occasionally as well. You can create most of them with the scripts found in the tables directory of the recipes distribution. The baseball1 directory contains instructions for creating the tables used in the examples relating to the baseball1.com baseball database.

Using the mysql Client Program

Writing MySQL-Based Programs

Record Selection Techniques

Working with Strings

Working with Dates and Times

Sorting Query Results

Generating Summaries

Modifying Tables with ALTER TABLE

Obtaining and Using Metadata

Importing and Exporting Data

Generating and Using Sequences

Using Multiple Tables

Statistical Techniques

Handling Duplicates

Performing Transactions

Introduction to MySQL on the Web

Incorporating Query Resultsinto Web Pages

Processing Web Input with MySQL

Using MySQL-Based Web Session Management

Appendix A. Obtaining MySQL Software

Appendix B. JSP and Tomcat Primer

Appendix C. References



MySQL Cookbook
MySQL Cookbook
ISBN: 059652708X
EAN: 2147483647
Year: 2005
Pages: 412
Authors: Paul DuBois

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