How to insert,update,delete and show data in Magento

Suppose, I have a module named mynews. Here follows the code to select, insert, update, and delete data from the news table
1. INSERT DATA
$data contains array of data to be inserted. The key of the array should be the database table’s field name and the value should be the value to be inserted.

<?php
$data = array('title'=>'hello there','content'=>'how are you? i am fine over here.','status'=>1);
$model = Mage::getModel('mynews/mynews')->setData($data);
try {
    $insertId = $model->save()->getId();
    echo "Data successfully inserted. Insert ID: ".$insertId;
} catch (Exception $e){
 echo $e->getMessage();   
}
?>

2. SELECT DATA

<?php
$item->getData(); //prints array of data from 'news' table.
$item->getTitle(); //prints the only the title field.
?>

Similarly, to print content, we need to write $item->getContent().

<?php
$model = Mage::getModel('mynews/mynews');
$collection = $model->getCollection();
foreach($collection as $item){
print_r($item->getData());
print_r($item->getTitle());
}
?>

3. SELECT DATA
$id is the database table row id to be updated. $data contains array of data to be updated. The key of the array should be the database table’s field name and the value should be the value to be updated.

<?php
// $id = $this->getRequest()->getParam('id');
$id = 2;
$data = array('title'=>'hello test','content'=>'test how are you?','status'=>0);
$model = Mage::getModel('mynews/mynews')->load($id)->addData($data);
try {
    $model->setId($id)->save();
    echo "Data updated successfully.";

} catch (Exception $e){
    echo $e->getMessage(); 
}
?>

4. DELETE DATA

<?php
$id is the database table row id to be deleted.
// $id = $this->getRequest()->getParam('id');
$id = 3;
$model = Mage::getModel('mynews/mynews');
try {
    $model->setId($id)->delete();
    echo "Data deleted successfully.";

} catch (Exception $e){
    echo $e->getMessage(); 
}
?>

In this way you can perform select, insert, update and delete in your custom module and in any magento code. Hope this helps. Thanks.