Pure ORM Component

Object-Relational Mapping (ORM)

How To Connect:

Instantiate the Database connection giving database settings

$db = new Pure\ORM\Database("mysql", "hostname", "database", "user", "password", array(PDO_attributes));

or bind a ready PDO instance

$db = Pure\ORM\Database::bind($pdo);

It is also possible to define the database settings and apply for connection at the first time in which a query is called. This means that no database connection time is lost in pages in which there are no data queries.
```
Pure\ORM\Database::bind("mysql", "hostname", "database", "user", "password", array(PDO_attributes));
```
After the step 1 or 2, the database instance can be globally accessed by the singleton pattern:
```
$db = Pure\ORM\Database::main();
```

It is possible to change the current database instance:

$db1 = new Pure\ORM\Database(....);
$db2 = new Pure\ORM\Database(....);

$current = Pure\ORM\Database::main(); // this refers to $db2
Pure\ORM\Database::change($db1);
$current = Pure\ORM\Database::main(); // this refers to $db1

Close the connection by:
```
$db->close();
```

How To execute queries:

Getting a row:

$data = $db->fetch("SELECT email, username FROM users WHERE username = ?", array("Mario"));

$data = $db->select("users", array( 'email', 'username' ), "username = Mario" );

Getting multiple rows:

$data = $db->fetchAll("SELECT id, username FROM users");

$data = $db->selectAll("users", array( 'email', 'username' ), $condition);

Insert a row:

$result = $db->insert("users", array( "name" => "Mario", "email" => "mario.rossi@email.com"));

$result will be true or false

Update existing row:

$result = $db->update("users", "id = 1", array( "name" => "Roberto" ) );

Remove rows:

$result = $db->delete("users", "id = 1");

In order to debug the code, during the development phase, the error reporting should be activated

Pure\ORM\Database::main()->error_reporting(true);

How To define Models

The Model class let to map Schema and data to objects. First of all, a model class declaration is required. The define function let the developer to specify the model's properties.

class User extends Model
{
    public static function define($schema)
    {
        $schema->id();
        $schema->char('username')->unique();
        $schema->char('password');
        $schema->char('email');
        $schema->boolean('active')->default(true);
    }
}

Once a model is defined, it is easy to map data and queries with objects.

Instantiate the model:

$model = new User;
$model->username = 'mariorossi98';
$model->password = 'mypassword';
$model->email = 'mario.rossi@mai.it';

$model->save();

The save method can be used to insert or update sql data.

The framework will perform this choice by itself.

Find models:
```
$model = User::find('id = 1');
```

Delete data:

$model = User::find('id = 1');
// ....
$model->erase();

Retrieve multiple models:
```
$models = User::all($condition = null);
```
Get the table name:
```
$table_name = User::table();
```

Use the methods 'data' and 'json' to encode the model to a simple reprensetation that should by easily shared.

var_dump($model->data());
/*
[
  'id' => 1,
  'username' => 'mariorossi98',
  'password' => 'mypassword',
  'email' => 'mario.rossi@mai.it'
  'active' => 1
]
*/

var_dump($model->json());
/*
{
  "id":1,
  "username":"mariorossi98",
  "mypassword":"root",
  "email":"mario.rossi@mai.it",
  "active":1
}
*/

How To specify the model's table name

If not speficied, the table name will be the model class name + 's'.

For example, User -> 'Users'. Otherwise, is it also possible to specify the table:

class User extends Model
{
    public static function table()
    {
        return 'my_custom_table_name';
    }
    
    public static function define($schema)
    {
        $schema->id();
        $schema->char('username')->unique();
        $schema->char('password');
        $schema->char('email');
        $schema->boolean('active')->default(true);
    }
}

How To define the model's properties

- $schema->id($name = 'id') // adds an id property (integer, primary, increments)
- $schema->boolean($name)
- $schema->integer($name)
- $schema->float($name)
- $schema->char($name, $size = 30)
- $schema->text($name)
- $schema->date($name)
- $schema->time($name)
- $schema->datetime($name)
- $schema->timestamps()     // adds two datetime properties: 'created_at', 'updated_at'

Properties can be specified by descriptors:

- default($value)   // specifies the property's default value
- increments()      // 'auto_increment'
- nullable()        // by default, all properties are not nullable
- primary()         // primary key
- unique()          // unique value
- unsigned()        // valid for numbers
- link(OtherModelClass, OtherModelProperty) // foreign key

Property's descriptors can be concatenated like in the examples below:

$schema->integer('id')->increments()->primary();
$schema->text('notes')->nullable();
$schema->char('username', 50)->unique();
$schema->boolean('active')->default(true);

According to define foreing keys, use the 'link' descriptor, link in this example

class Book extends Model
{    
    public static function define($schema)
    {
        $schema->id();
        $schema->char('name')->unique();
        $schema->integer('bought_by')->link(User::class, 'id');
    }
}

Schema Management

The Schema utility can be used to create, delete and check the existence of a named table into the database.

Check if a table exists:

$result = Pure\ORM\Schema::exists(User::class);

Delete a table:

$result = Pure\ORM\Schema::drop(User::class);

Create a table:

$result = Pure\ORM\Schema::create(User::class);

Is also possible to delete all the table entries:
```
$result = Pure\ORM\Schema::clear(User::class);
```

It is possible to fill test data at the schema's creation time. To perform this operation, the seed function in the Model should be overriden.

class User extends Model
{
    public static function define($schema)
    {
        $schema->id();
        $schema->char('username')->unique();
        $schema->char('password');
        $schema->char('email');
        $schema->boolean('active')->default(true);
    }
    
    // executed only at the schema creation
    public static function seed()
    {
        $model = new User;
        $model->username = 'test';
        $model->password = 'test';
        $model->email = 'test@mail.com';
        $model->save();
        
        // ... other models
    }
}