Check for successful connection Connect to the Jobs database
Assign data values from the data entry form to variables
Execute an SQL command to add the record to the JobsList table
Chapter 2 Communications and Internet technologies
Make a connection to the web and database server
Figure 2.10 Processing the PHP script
Summary Most network applications use the client–server model. Applications include database, email, file transfer and web servers. The Internet is the hardware infrastructure – consisting of routers, gateways and networks – which supports global communication. The World Wide Web is the content which is available from various web servers. Various communications systems support the Internet including: the Public Service Telephone Network (PSTN), dedicated lines and the cell phone network. Communication signals use copper and fibre-optic cabling, radio waves, microwaves and satellites.
Bit-streaming is used to access content from servers to provide video and sound to users either on-demand or in real time. The packet-switching network on the Internet uses IP addressing. An IP address can be either private or public. Resources available on the WWW are identified using a Uniform Resource Locator (URL). The Domain Name Service has the task of mapping all URLs to an actual IP address. Web pages can contain program code in addition to HTML tags. This code is processed either by the client computer (‘client-side scripting’) or on the server (‘server-side scripting’). JavaScript is used for client-side code; PHP is used for serverside code.
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