PHP and MySQL Web Development - P58 ppsx

257 Restoring Your MySQL Database Loading Data from a File One useful feature of MySQL that we have not yet discussed is the LOAD DATA INFILE statement.This can be used to load table dat

257 Restoring Your MySQL Database

Loading Data from a File

One useful feature of MySQL that we have not yet discussed is the LOAD DATA INFILE

statement.This can be used to load table data in from a file It executes very quickly

This is a flexible command with many options, but typical usage is something like the following:

LOAD DATA INFILE "newbooks.txt" INTO TABLE books;

This will read row data from the file newbooks.txtinto the table books By default, data fields in the file must be separated by tabs and enclosed in single quotes, and each row must be separated by a newline (\n) Special characters must be escaped out with a slash (\) All these characteristics are configurable with the various options of the LOAD state-ment—see the MySQL manual for more details

To use the LOAD DATA INFILEstatement, a user must have the FILE privilege dis-cussed earlier

Backing Up Your MySQL Database

In MySQL, there are two ways to do a backup

The first way is to lock the tables while you copy the physical files, using a LOCK TABLES command.This has the syntax:

LOCK TABLES table lock_type [, table lock_type ]

Each table should be the name of a table, and the lock type either READor WRITE For a backup, you should only need a READlock Users and scripts will still be able to run read-only queries while you make your backup If you have a reasonable volume of queries that alter the database, such as customer orders, this is not a practical solution

The second, and superior, method is using the mysql_dumpcommand.Typical usage is something such as

mysqldump opt all-databases > all.sql

This will dump a set of all the SQL required to reconstruct the database to the file called

all.sql You should then stop the mysqldprocess for a moment and restart it with the

log-update[=logfile]option.The updates stored in the log file will give you the changes made since your dump (Obviously you should back up the log files in any nor-mal file backup.)

Restoring Your MySQL Database

If you need to restore your MySQL database, there are, again, a couple of approaches

If the problem is a corrupted table, you can run myisamchkwith the -r(repair) option

258 Chapter 11 Advanced MySQL

If you’ve used the first method for backup, then you can copy the data files back into the same locations in a new MySQL installation

If you have used the second method for backup, there are a couple of steps First, you need to run the queries in your dump file.This will reconstruct the database up to the point where you dumped that file Second, you will need to update the database to the point stored in the log files Under UNIX, you can run a command such as

ls -1 -t -r hostname.[0-9]* | xargs cat | mysql

to process the log files in the correct order

More information about the process of MySQL backup and recovery can be found at the MySQL Web site:

http://www.mysql.org

Further Reading

In these chapters on MySQL, we have focused on the uses and parts of the system most relevant to Web development, and to linking MySQL with PHP

If you want to know more, particularly with regard to non-Web applications, or MySQL administration, you can visit the MySQL Web site at

http://www.mysql.com

You might also want to consult Paul Dubois’ book MySQL, available from New Riders

Publishing

Next

We have now covered the fundamentals of PHP and MySQL In Chapter 12, “Running

an E-commerce Site,” we will look at the e-commerce and security aspects of setting up database-backed Web sites

E-commerce and Security

12 Running an E-commerce Site

13 E-commerce Security Issues

14 Implementing Authentication with PHP and MySQL

15 Implementing Security Transactions with PHP and MySQL

Running an E-commerce Site

THIS CHAPTER INTRODUCES SOME OF THE ISSUESinvolved in specifying, designing, building, and maintaining an e-commerce site effectively.We will examine your plan, possible risks, and some ways to make a Web site pay its own way

We will cover

n What you want to achieve with your e-commerce site

n Types of commercial Web site

n Risks and threats

n Deciding on a strategy

What Do You Want to Achieve?

Before spending too much time worrying about the implementation details of your Web site, you should have firm goals in mind, and a reasonably detailed plan leading to meet-ing those goals

In this book, we make the assumption that you are building a commercial Web site Presumably then, making money is one of your goals

There are many ways to take a commercial approach to the Internet Perhaps you want to advertise your offline services or sell a real-world product online Maybe you have a product that can be sold and provided online Perhaps your site is not directly intended to generate revenue, but instead supports offline activities or acts as a cheaper alternative to present activities

Types of Commercial Web Sites

Commercial Web sites generally perform one or more of the following activities:

n Publish company information through online brochures Take orders for goods or services