$_ = Company::_();


$company = Company::get(10);        // SELECT * FROM `company` WHERE `id` = 10


$companies = Company::filter(       // SELECT * FROM `company`
    $_('name')->like('%oo%'),       // WHERE ( `name` LIKE '%oo%'
    $_('is_public')->eq(true)       // AND `is_pubilc` = 1 )
)->or(
    $_('employees')->gt('10000')    // OR ( `employees` > 10000 )
);


foreach ($companies as $company) {
    echo $company->name;
    echo $company->ceo->name;       // SELECT * FROM `employee` WHERE 
                                    // `id` = {$company->ceo}
    echo $company->ceo->sex->text();
}


$companies_ceo_born_after_1972 = Company::filter(
    $_('ceo')->_('born')->gt(1972)

    // SELECT `id` FROM `company` WHERE ( `ceo_id` 
    //     IN (SELECT `id` FROM `employee` WHERE `born` > '1972'))
);

class Company extends Yapo\Yapo {

    public static function table() {
        return 'CompanyTable';
    }

    protected static function define_fields($define) {

        $define('name')             ->as('name'); // ->of('CompanyTable');

        $define('founded')          ->as('founded'); // ->of('CompanyTable');

        $define('symbol')           ->as('nasdaq_symbol'); // ->of('CompanyTable');

        $define('description')      ->as('description')->of('CompanyDetailTable')
                                    ->using('id');

        $define('ceo')              ->as('Employee')
                                    ->using('ceo');

        $define('employees')        ->as('Employee')
                                    ->with('company');

        $define('brief')            ->as(function($row) {
                                        return "{$row['name']}, founded in {$row['founded']}.";
                                    }); // ->of('CompanyTable');

        $define('special')          ->as('special')->switch(array(
                                        '0' => 'Company',
                                        '1' => 'SpecialCompany'
                                    ));
    }

    // define instance methods
    public function introduce() {
        return $this->brief;
    }

}

/*
 * SpecialCompany is a submodel
 */
class SpecialCompany extends Company {

    protected static function define_fields($define) {
        // inherit all fields defined in Company

        $define('why')          ->as('why')->of('SpecialCompanyTable')
                                ->using('id');

    }

    // overwrite Company::introduce()
    public function introduce() {
        return "[{$this->why}] {$this->brief}";
    }
}

class Employee extends Yapo\Yapo {

    public static function table() {
        return 'EmployeeTable';
    }

    protected static function define_fields($define) {

        $define('name')             ->as('name');

        $define('sex')              ->as('sex')
                                    ->enum(array(
                                        0 => '?',
                                        1 => 'Male',
                                        2 => 'Female'
                                    ));

        $define('company')          ->as('Company')->using('company_id');
    }

}

class CompanyTable extends Yapo\YapoTable {

    public static function master() {
        return new Yapo\YapoConfig(
            $dsn      = TEST_DSN,
            $user     = TEST_USER,
            $password = TEST_PASS,
            $table    = 'company',
            $pk       = 'id'
        );
    }
}

class CompanyDetailTable extends Yapo\YapoTable {

    public static function master() {
        return new Yapo\YapoConfig(
            $dsn      = TEST_DSN,
            $user     = TEST_USER,
            $password = TEST_PASS,
            $table    = 'company_detail',
            $pk       = 'id'
        );
    }
}

class SpecialCompanyTable extends Yapo\YapoCachedTable {

    public static function master() {
        return new Yapo\YapoConfig(
            $dsn      = TEST_DSN,
            $user     = TEST_USER,
            $password = TEST_PASS,
            $table    = 'special_company',
            $pk       = 'id'
        );
    }
}

class EmployeeTable extends Yapo\YapoTable {

    public static function master() {
        return new Yapo\YapoConfig(
            $dsn      = TEST_DSN,
            $user     = TEST_USER,
            $password = TEST_PASS,
            $table    = 'employee',
            $pk       = 'id'
        );
    }
}