Hello Readers,
In this blog i am going to show you "How to select, insert, add, update/edit and delete data in the Magento.
Lets Suppose, If you have database table named 'slider' with the following fields
id(int,primay key), title(varchar), content(text) & status(smallint, value 0 or 1).
& you have a module name 'Slider'. then, follow the below code to implement CRUD operations in magento.

Select Data in Magento

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

Here,
item->getData() prints all data from ‘slider’ table.
$item->getTitle() prints only one field i.e title from 'slider' table.

Insert Data

$data = array('title'=>'slide1','content'=>'this is my first slide','status'=>1);
$model = Mage::getModel('slider/slider')->setData($data);
$model->save();

Here, $data contains array of data & 'title', 'content', 'status' is key of the array which should be database table’s field name.

Update Data

$id = 1;
$data = array('title'=>'slide one','content'=>'this is first slide updated','status'=>1);
$model = Mage::getModel('slider/slider')->load($id)->setData($data);
$model->setId($id)->save();

Here, $id is the database table id to be updated & $data contains array of data to be updated.

Delete Data

$id = 1; // $id is table id to be deleted.
$model = Mage::getModel('slider/slider');
$model->setId($id)->delete();