Get data from database in Joomla 2.5 [closed] - joomla

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Closed 9 years ago.
How to extract data from single database table?
For example, i need data from table: categories, column: description with id 1 ?

Answer 1

As long as you are trying to write a Joomla component, I recommend you to start learning writing your code with MVC architecture. Joomla Documentation on this subject is available here. Anyhow, I'm gonna give you a simple but temporary solution and you have to rewrite it later using Joomla's MVC.
I presume that you want to select column1 and column2 data from your #__example_table and show then in a simple table.
First, you need to create a component with an empty view. You can use this online tool for creating a component at a glance; and of course it's free for creating components with empty views. After building, downloading and installing your component, let's call it com_mycomponent, there will be a folder called com_mycomponent in your /components folder. open it up and you'll see a views folder and inside it there's gonna be a folder for your view that I'm gonna call that myview.
In your view folder, there's a file called view.html.php which contains you view's class and also you can see a folder called tmpl which contains a default.php file for your view's template.
Now open view.html.php in an editor and create a public attribute called $items and getData() method after display() method like this:
<?php
class MycomponentViewMyview extends JView {
.
.
.
public $items;
public function display($tpl = null) {
.
.
.
$this->items = $this->getData();
parent::display($tpl);
}
public function getData() {
$db = JFactory::getDbo();
$query = $db->getQuery(true);
$query->select(array('column1', 'column2'));
$query->from('#__example_table');
$query->where('condition = 1');
$query->order('id DESC');
$db->setQuery($query);
$results = $db->loadObjectList();
if (!empty($results)) {
return $results;
}
return false;
}
}
In this example I've used Joomla's database API which are described here; and consider that dots means rest of the codes which you don't need to change.
Now open /components/com_mycomponent/views/myview/tmpl/defailt.php and delete everything here and write something like this:
<?php
defined('_JEXEC') or die; // No direct access
if (count($this->items)) {
?>
<table style="width: 100%">
<thead>
<tr>
<th>Column 1</th>
<th>Column 2</th>
</tr>
</thead>
<tbody>
<?php foreach ($this->items as $item) { ?>
<tr>
<td><?php echo $item->column1; ?></td>
<td><?php echo $item->column2; ?></td>
</tr>
<?php } ?>
</tbody>
</table>
<?php
} else {
echo 'Sorry! No data found...';
}
I think the example is quite clear and there's no need of explanation, but I'm gonna give you a brief explanation about what's happening. First of all we created an method to get data from database and store them in a variable which is accessible from outside. Then we call that method from display method which is somehow the constructor of the view class. Then in the view's template I used a loop for the records stored in $items variable and show them in table rows.
I tried to explain the solution in most simple possible way so that everyone could use it, and if it bothers you, I'm sorry.
Feel free to ask question and correct me.