Connecting to underlying data sources: Difference between revisions

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# The name of the database.
# The name of the database.


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


<syntaxhighlight lang="php">
<syntaxhighlight lang="php">
<?php
<?php
// this file should be named database_inc.php
$connect = mysqli_connect("localhost","YOURUSERNAME","YOURPASSWORD","YOURDATABASE");
$connect = mysqli_connect("localhost","YOURUSERNAME","YOURPASSWORD","YOURDATABASE");
// Check connection
// the code below handles errors
if (mysqli_connect_errno())
if (mysqli_connect_errno())
{
{
echo "Failed to connect to MySQL: " . mysqli_connect_error();
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
}
?>
</syntaxhighlight>
As another example, you can connect to a flat file (or plain text) data source using file open, file read and file write operations<ref>http://php.net/manual/en/function.fopen.php</ref>
<syntaxhighlight lang="php">
<?php
$handle = fopen("c:\\folder\\resource.txt", "r");
?>
?>
</syntaxhighlight>
</syntaxhighlight>

Revision as of 09:08, 26 April 2018

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");
?>

Do you understand this?[edit]

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[edit]

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

  • Describe how web pages can be connected to underlying data sources.

References[edit]

  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.

Give a detailed account or picture of a situation, event, pattern or process.

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