In Elefant, the main way you'll likely be interfacing with the database is by creating custom models to encapsulate your application logic. This helps keep your custom logic well-organized, and keeps it from bleeding into your handler scripts, which you should try to limit to marshalling requests to the appropriate Model methods and passing onto the appropriate view (see Templates).
For the examples below, we'll assume the following database schema:
create table mytable (
id int not null auto_increment primary key,
name char(48) not null,
age int not null,
gender enum('m','f') not null,
index (age),
index (gender)
);
Now we need to make a class for our custom model. In the myapp app created from Page routing and handler basics, create a file called apps/myapp/models/Mytable.php and add the following code:
<?php
class Mytable extends Model {}
?>
That's all that is required to define a model. We can now use it in a handler like this:
<?php
// create a new object with some data
$m = new Mytable (array (
'name' => 'John',
'age' => 30,
'gender' => 'm'
));
// save the data (insert or update)
$m->put ();
// output the id from the insertion
echo $m->id;
// update a value
$m->age = 31;
$m->put ();
// remove the item
$m->remove ();
?>
This gives us a base object with very little code that handles all our CRUD operations for us in a consistent manner. We can also do custom queries like this:
<?php
$res = Mytable::query ()
->where ('age > 30')
->where ('gender', 'm')
->order ('name asc')
->fetch (20, 0);
foreach ($res as $row) {
// each $row is a Mytable object
echo $row->name;
}
?>
If you're using this from an existing object, make sure not to forget the query() method at the start of the query to make sure the initial query state has been reset:
<?php
$res = Mytable::query ()
->where ('age > 30')
->where ('gender', 'm')
->order ('name asc')
->fetch (20, 0);
foreach ($res as $row) {
// each $row is a Mytable object
echo $row->name;
}
?>
Let's use this to extend our model with a couple custom methods:
<?php
class Mytable extends Model {
public function by_age ($age) {
return self::query ()->where ('age', $age)->fetch ();
}
public function by_gender ($gender) {
return self::query ()->where ('gender', $gender)->fetch ();
}
}
?>
Now we can say things like $res = Mytable::by_age ($age) and $res = Mytable::by_gender ($gender). Using this technique, we can encapsulate our model logic and help keep ourselves organized and our handlers short and sweet.
Elefant's models provide powerful relationship modelling, including one-to-many, many-to-many, one-to-one, and belongs-to.
Read more about modelling relationships in Elefant here.
Models support the same data validation types as forms. You can define validation rules like this:
<?php
class Mytable extends Model {
public $verify = array (
'email' => array (
'email' => 1,
'contains' => '@ourdomain.com'
),
'name' => array (
'not empty' => 1
)
);
}
?>
Alternately, you can define your validations in a separate INI-formatted file and reference it like this:
<?php
class Mytable extends Model {
public $verify = 'apps/myapp/forms/mytable.php';
}
?>
For more info on input validation, see Forms and input validation.