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Web Technologies-I

Notes the “mysqldump” utility for this purpose. The command is issued from the command line, not
within the “mysql” program.
mysqldump -uuser -ppassword -hhost.domain.com database > filename.sql
• -u specifies the database user account to use
• -p specifies the database user password to use

• -h specifies the database server to connect to
• database specifies the database to act on
• > filename.sql directs the output to a file. Normally output is directed to the screen.

The output of a mysqldump can be directed back into a blank database to recreate a complete
set of tables and data. This is especially handy if you develop a structure on a staging system
and need to quickly and easily move the whole contents of a database to a new system. Here
is the command to do that using the “mysql” utility.
mysql -uuser -ppassword -hhost.domain.com database < filename.sql
• -u specifies the database user account to use

• -p specifies the database user password to use
• -h specifies the database server to connect to
• database specifies the database to act on

• < filename.sql directs the mysql program to read instructions from a file instead of the
command line.

Develop a PHP program to connect your page from the database.

10.3 PEAR DB Basics

PEAR supplies a number of open source extensions to PHP including its DB package, which
provides a database abstraction layer, so that the PHP programmer does not have to worry
about all the APIs for different databases.

10.3.1 Advantages and Disadvantages of PEAR DB
Whether or not you decide to use PEAR DB or a similar database abstraction layer depends
on your needs. If you need to be able to work on many applications and get your work done
quickly, then PEAR DB is certainly helpful. If performance is key, then you may find the extra
weight of PEAR DB to be prohibitive.
10.3.2 Why use a database abstraction layer?

One big benefit of using a database abstraction layer like PEAR DB is portability. PEAR DB
allows you to use a single API for working with many different types of databases. So if you
decide to move to another database, you will not have to rewrite all your code.

Another benefit is code simplification. If your application involves multiple databases of different
flavours or you work on many applications each of which uses a different type of database, you
would normally have to learn the APIs for each of the databases you would be working with.
Again, PEAR DB allows you to work with all these databases using the same API.

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