Flat files are only feasible in very low to low volume websites as flat files have 3 inherent weaknesses: 1.The inability to index data. This makes it necessary to potentially read ALL data sequentially. This is a major problem if there are a lot of records in flat file because time required to read flat file is proportionate to number of records in flat file. 2.The inability to efficiently control access by users to data 3.The inefficient storage of data. In most cases, data would not be encrypted or compressed as this would exacerbate problem no. 1 above

The alternative which is, in my opinion, only feasible method, is to store data in a database. One of most prevalent databases in use is MySQL. Data that is stored in a database can easily be indexed, managed and stored efficiently. Besides that, most databases also provide a suite of accompanying utilities that allow database administrator to maintain database – for example, backup and restore, etc.

Websites scripted using PHP are very well suited for MySQL database as PHP has a custom and integrated MySQL module that communicates very efficiently with MySQL. PHP can also communicate with MySQL through standard ODBC as MySQL is ODBC-compliant, However, this will not be as efficient as using custom MySQL module for PHP.

The rest of this article is a tutorial on how to use PHP to: 1.Connect to a MySQL database 2.Execute standard SQL statements against MySQL database

Starting a Session with MySQL

Before PHP script can communicate with database to query, insert or update database, PHP script will first need to connect to MySQL server and specify which database in MySQL server to operate on.

The mysql_connect() and mysql_select_db() functions are provided for this purpose. In order to connect to MySQL server, server name/address; a username; and a valid password is required. Once a connection is successful, database needs to be specified.

XML (Extensible Markup Language) 1.0 standard was published February 10, 1998. XML was born from shortcomings of SGML [Structured Generalized Markup Language] which

was hugely complex, massively flexible and just plain hard to work with for many developers. XML has taken off because it has all best of SGML without many of weakness.

XML Goal

XML took us beyond mere presentation of information and into realm of representation

of information. This content is not just a mass of data to be rendered solely for viewing

on a web browser. Now content could be structured and meaning attached to this

structure could be transmitted as well.

HTML's difficulties: 1- HTML does not reveal anything about information to which HTML tags are applied.

HTML tag names don't describe what content is, they only imply how content appears.

For example html tag "Microsoft" appears on a web browser but HTML can not

tell is it a computer corporation? A Software? A Brand name?

2- Web applications relied too much on scripts at server to process data.

This makes web slow and contributes to internet traffic.

3- You can't add new tags to HTML Language that are meaningful and useful.

4- HTML is a presentation technology only.

XML Success The Java technology, enables browsers to function as generalized application platforms. The result is True platform independence. XML provides information rich in metadata specified

in a standard format, XML and Java technology make it possible for more of an application's

work to be processed at a client side. This contrasts with tendency of HTML pages to rely

on a script back at server. With XML and Java technology, more client-based application

processing could reduce network and internet traffic, making web faster.

XML challenges Converting any information from a display format such as HTML, RTF, MIF, or PostScript to a

structured format like XML will require that you understand what your information really

contains. This requires a document analysis and determination of information semantics on which different parts of your enterprise rely. Many enterprises in different business sectors

have established industry standard information models that can be expressed in XML and, more

importantly, can be shared.

Once relevant information models and their expressions in XML are constructed, effort to convert existing information into XML format can proceed. It may or may not be painful,

depending on condition of existing documents. These efforts can be done in house, or they

can be completed with help of qualified consultants.

XML Resources: Easy XML is a simple XML editor that aids in rapid building of XML applications. Microsoft XML for SQL Web allows you to query database tables and receive results as an XML document.