Greg ORM

A lightweight but powerful ORM(Object-Relational Mapping) library for PHP.

Gest Started with establishing a Database Connection, create an Active Record Model of a database table and write your first queries using the Query Builder.

Why use Greg ORM?

You can read about it in the next article: pending

Get Started

• Requirements
• Installation
• Supported Drivers
• Database Connection - Quick Start
• Query Builder - Quick Start
• Active Record Model - Quick Start

Requirements

• PHP Version ^7.1

Installation

You can add this library as a local, per-project dependency to your project using Composer:

composer require greg-md/php-orm

Supported Drivers

• MySQL
• SQLite

In progress:

• MS SQL
• PostgreSQL
• Oracle

Database Connection - Quick Start

There are two ways of creating a database connection:

1. Instantiate a database connection for a specific driver;
2. Instantiate a connection manager to store multiple database connections.

The connection manager implements the same connection strategy. This means that you can define a connection to act like it.

In the next example we will use a connection manager to store multiple connections of different drivers.

// Instantiate a Connection Manager
$manager = new \Greg\Orm\Connection\ConnectionManager();

// Register a MySQL connection
$manager->register('mysql_connection', function() {
    return new \Greg\Orm\Connection\MysqlConnection(
        new \Greg\Orm\Connection\Pdo('mysql:dbname=example_db;host=127.0.0.1', 'john', 'doe')
    );
});

// Register a SQLite connection
$manager->register('sqlite_connection', function() {
    return new \Greg\Orm\Connection\SqliteConnection(
        new \Greg\Orm\Connection\Pdo('sqlite:/var/db/example_db.sqlite')
    );
});

// Make the manager to act as "mysql_connection"
$manager->actAs('mysql_connection');

Now you can work with this manager:

// Fetch a statement from "sqlite_connection"
$manager->connection('sqlite_connection')
    ->select()
    ->from('Table')
    ->fetchAll();

// Fetch a statement from mysql_connection, which is used by default
$manager
    ->select()
    ->from('Table')
    ->fetchAll();

Full documentation can be found here.

Active Record Model - Quick Start

The Active Record Model represents a table schema, an entity or a collection of entities of that table, integrated with the Query Builder to speed up your coding process.

Let's say you have Users table:

CREATE TABLE `Users` (
  `Id` INT(10) UNSIGNED NOT NULL AUTO_INCREMENT,
  `Email` VARCHAR(255) NOT NULL,
  `Password` VARCHAR(32) NOT NULL,
  `SSN` VARCHAR(32) NULL,
  `FirstName` VARCHAR(50) NULL,
  `LastName` VARCHAR(50) NULL,
  `Active` TINYINT(1) UNSIGNED NOT NULL DEFAULT '1',
  PRIMARY KEY (`Id`),
  UNIQUE (`Email`),
  UNIQUE (`SSN`),
  KEY (`Password`),
  KEY (`FirstName`),
  KEY (`LastName`),
  KEY (`Active`)
);

Let's create the model for that table and configure it:

class UsersModel extends \Greg\Orm\Model
{
    // Define table alias. (optional)
    protected $alias = 'u';

    // Cast columns. (optional)
    protected $casts = [
        'Active' => 'boolean',
    ];

    // Table name (required)
    public function name(): string
    {
        return 'Users';
    }

    // Create abstract attribute "FullName". (optional)
    public function getFullNameAttribute(): string
    {
        return implode(' ', array_filter([$this['FirstName'], $this['LastName']]));
    }

    // Change "SSN" attribute. (optional)
    public function getSSNAttribute(): string
    {
        // Display only last 3 digits of the SSN.
        return str_repeat('*', 6) . substr($this['SSN'], -3, 3);
    }

    // Extend SQL Builder. (optional)
    public function whereIsNoFullName()
    {
        $this->whereIsNull('FirstName')->whereIsNull('LastName');

        return $this;
    }
}

Now, let's instantiate that model. The only thing you need is a Database Connection:

// Initialize the model.
$usersModel = new UsersModel($connection);

Working with table schema

// Display table name.
print_r($usersModel->name()); // result: Users

// Display auto-increment column.
print_r($usersModel->autoIncrement()); // result: Id

// Display primary keys.
print_r($usersModel->primary()); // result: ['Id']

// Display all unique keys.
print_r($usersModel->unique()); // result: [['Email'], ['SSN']]

Working with a single row

// Create a user.
$user = $usersModel->create([
    'Email' => '[email protected]',
    'Password' => password_hash('secret'),
    'SSN' => '123456789',
    'FirstName' => 'John',
    'LastName' => 'Doe',
]);

// Display user email.
print_r($user['Email']); // result: [email protected]

// Display user full name.
print_r($user['FullName']); // result: John Doe

print_r($user['SSN']); // result: ******789

// Display if user is active.
print_r($user['Active']); // result: true

// Display user's primary keys.
print_r($user->getPrimary()); // result: ['Id' => 1]

Working with a row set

// Create some users.
$usersModel->create([
   'Email' => '[email protected]',
   'Password' => password_hash('secret'),
   'Active' => true,
]);

$usersModel->create([
   'Email' => '[email protected]',
   'Password' => password_hash('secret'),
   'Active' => false,
]);

$usersModel->create([
   'Email' => '[email protected]',
   'Password' => password_hash('secret'),
   'Active' => false,
]);

// Fetch all inactive users from database.
$inactiveUsers = $usersModel->whereIsNot('Active')->fetchAll();

// Display users count.
print_r($inactiveUsers->count()); // result: 2

// Display users emails.
print_r($inactiveUsers->get('Email')); // result: ['[email protected]', '[email protected]']

// Activate all users in the row set.
$inactiveUsers->set('Active', true)->save();

print_r($inactiveUsers[0]['Active']); // result: true
print_r($inactiveUsers[1]['Active']); // result: true

Working with Query Builder

Select users that doesn't have first and last names.

$users = $usersModel
    ->whereIsNoFullName()
    ->orderAsc('Id')
    ->fetchAll();

Update an user:

$usersModel
    ->where('Id', 10)
    ->update(['Email' => '[email protected]']);

Full documentation can be found here.

Query Builder - Quick Start

The Query Builder provides an elegant way of creating SQL statements and clauses on different levels of complexity.

You can easily instantiate a Query Builder with a Database Connection.

Let's say you have Students table.

Find students names that lives in Chisinau and were born in 1990:

$students = $connection->select()
    ->columns('Id', 'Name')
    ->from('Students')
    ->where('City', 'Chisinau')
    ->whereYear('Birthday', 1990)
    ->fetchAll();

Update the grade of a student:

$connection->update()
    ->table('Students')
    ->set('Grade', 1400)
    ->where('Id', 10)
    ->execute();

Delete students that were not admitted in the current year:

$connection->delete()
    ->from('Students')
    ->whereIsNot('Admitted')
    ->execute();

Add a new student:

$query = $connection->insert()
    ->into('Students')
    ->data(['Name' => 'John Doe', 'Year' => 2017])
    ->execute();

Full documentation can be found here.

Documentation

• Database Connection
• Active Record Model
• Query Builder
• Migrations are under construction, but you can use Phinx in the meantime.

License

MIT © Grigorii Duca

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