Sloth Framework - Orm - Define Model

Defining ORM Model and Relationships

models\User.php

    use Sloths\Db\Model\Model;

    class User extend Model
    {
        // protected static $tableName = 'users' // by default
        // protected static $primaryKey = 'id' // by default

        protected static $columns = [
            'id'        => self::INT,
            'group_id'  => self::INT,
            'name'      => self::VARCHAR,
            'email'     => self::VARCHAR,
            'password'  => self::VARCHAR,
            'status'    => self::VARCHAR
        ];

        protected static $hasOne            = ['Profile'];
        protected static $belongsTo         = ['Group'];
        protected static $hasMany           = ['Posts'];
        protected static $hasManyThrough    = [
            'Roles' => ['model' => 'Roles', 'throughModel' => 'UserRole']
        ];
    }

models\Profile.php

    use Sloths\Db\Model\Model;

    class Profile extend Model
    {
        protected static $primaryKey = 'user_id';

        protected static $columns = [
            'user_id'       => self::INT,
            'resume'        => self::TEXT,
            'modified_time' => self::DATETIME
        ];

        protected static $belongsTo = ['User'];
    }

models\Group.php

    use Sloths\Db\Model\Model;

    class Group extend Model
    {
        protected static $columns = [
            'id'    => self::INT,
            'name'  => self::VARCHAR
        ];

        protected static $hasMany = ['Users'];
    }

models\Role.php

    use Sloths\Db\Model\Model;

    class Role extend Model
    {
        protected static $columns = [
            'id'    => self::INT,
            'name'  => self::VARCHAR
        ];

        protected static $hasManyThrough = [
            'Users' => ['model' => 'User', 'throughModel' => 'UserRole']
        ];
    }

models\UserRole.php

    use Sloths\Db\Model\Model;

    class UserRole extend Model
    {
        protected static $columns = [
            'user_id'   => self::INT,
            'role_id'   => self::INT
        ];
    }

models\Posts.php

    use Sloths\Db\Model\Model;

    class Post extend Model
    {
        protected static $columns = [
            'id'            => self::INT,
            'creator_id'    => self::INT,
            'title'         => self::VARCHAR,
            'content'       => self::TEXT,
            'created_time'  => self::DATETIME,
            'modified_time' => self::DATETIME
        ];

        protected static $belongsTo = ['Users'];
    }