Web software for add deleting updating data
What’s important to see here is that the value returned by .
As the My SQL server is a completely separate piece of software from the web server, we must consider the possibility that the server may be unavailable or inaccessible due to a network outage, or because the username/password combination you provided is rejected by the server.
Since you'd probably prefer to keep this kind of technical information hidden once your site is live on the Web, it's common to switch off these errors on production servers.
By default, when PHP connects to My SQL, it once again uses the simpler ISO-8859-1 encoding instead of UTF-8.So, at one end of the system you have a visitor to your site who uses a web browser to request a page, and expects to receive a standard HTML document in return.At the other end you have the content of your site, which sits in one or more tables in a My SQL database that understands only how to respond to SQL queries (commands).As shown in the figure above, the PHP scripting language is the go-between that speaks both languages.It processes the page request and fetches the data from the My SQL database (using SQL queries just like those you used to create a table of jokes in Chapter 2: Introducing My SQL), then spits it out dynamically as the nicely formatted HTML page that the browser expects.