Apache: The Definitive Guide, 3rd Edition

Databases

Many serious web sites will need a database in back. In the authors’ experience, an excellent choice is MySQL, freeware made in Scandinavia by intelligent and civilized people. Download it from http://www.mysql.com. It uses a variant of the more-or-less standard SQL query language. You will need a book on SQL: Understanding SQL by Martin Gruber (Sybex, 1990) tells you more than you need to know, although the SQL syntax described is sometimes a little different from MySQL’s. Another option is SQL in a Nutshell by Kevin Kline (O’Reilly, 2000). MySQL is fast, reliable, and so easy to use that a lot of the time you can forget it is there. You link to MySQL from your scripts through the DBI module. Download it from CPAN (http://www.cpan.org/) if it doesn’t come with Perl. You will need some documentation on DBI — try http://www.symbolstone.org/technology/perl/DBI/doc/faq.html. There is also an O’Reilly book on DBI, Programming the Perl DBI by Alligator Descartes and Tim Bunce. In practice, you don’t need to know very much about DBI because you only need to access it in five different ways. See the lines marked 'A', 'B', 'C', 'D', and 'E' in script as follows:

'A' to open a database
'B' to execute a single command - which could equally well have been typed at the 
keyboard as a MySQL command line.
'C' to retrieve, display, process fields from a set of database records. A very nice 
thing about MySQL is that you can use the 'select *' command, which will make all the fields available ...