Connecting to underlying data sources

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Web Science[1]

A webpage can be connected to a data source. A datasource can be a relational database, a flat-file data source (such as a JSON file or an XML file or just a simple plaintext file).

In order to connect to an underlying datasource, we generally require three things:

  1. The location of the database. In many cases this is localhost but there is NO REQUIREMENT that the database is on the same server as the webpage.
  2. The credentials to authenticate (which ois usually a username and password)
  3. The name of the database.

As an example, the code below creates a connection to a relational database:

<?php
$connect = mysqli_connect("localhost","YOURUSERNAME","YOURPASSWORD","YOURDATABASE");
//  the code below handles errors
if (mysqli_connect_errno())
{
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
?>

As another example, you can connect to a flat file (or plain text) data source using file open, file read and file write operations[2]

<?php
$handle = fopen("c:\\folder\\resource.txt", "r");
?>

When a web page connects to an underlying datasource, it is protected access, meaning a web user cannot see the authentication details being passed to the database.

Do you understand this?

Students will not be expected to write code to indicate how the connection is made, but should understand the principles of connecting to an underlying data source.

Standards

These standards are used from the IB Computer Science Subject Guide[3]

  • DescribeGive a detailed account or picture of a situation, event, pattern or process. how web pages can be connected to underlying data sources.

References

  1. http://www.flaticon.com/
  2. http://php.net/manual/en/function.fopen.php
  3. IB Diploma Programme Computer science guide (first examinations 2014). Cardiff, Wales, United Kingdom: International Baccalaureate Organization. January 2012.