Question

Here’s my database schema:

create table Personas
(
    id int primary key AUTO_INCREMENT,
    Nombre varchar(255),
    Apellidos varchar(255),
    FechaDeNacimiento date,
    Sexo Bool,
    CarnetDeIdentidad varchar(255)
);

create table Tutors
(
    id int primary key AUTO_INCREMENT,
    persona_id int,
    FOREIGN KEY (persona_id) REFERENCES Personas(id)
);

create table Alumnos
(
    id int primary key AUTO_INCREMENT,
    persona_id int,
    FOREIGN KEY (persona_id) REFERENCES Personas(id)
);

create table CoordinadorDeProgramas
(
    id int primary key AUTO_INCREMENT,
    persona_id int,
    FOREIGN KEY (persona_id) REFERENCES Personas(id)
);

And here are my Model declarations:

<?php
class Alumno extends AppModel {
    public $belongsTo = 'Persona';
}

<?php
class Coordinadordeprograma extends AppModel {
    public $belongsTo = 'Persona';
}

<?php
class Tutor extends AppModel {
    public $belongsTo = 'Persona';
}

<?php
class Persona extends AppModel {
    public $hasOne = array('Alumno', 'Tutor', 'Coordinadordeprograma');
}

In my Controller I just want to fetch all Persona records if they have a foreign key relationship in Alumnos (for example).

Here’s my code, I hope it illustrates what I’m trying to do:

public function filter($type = null) {
    if ($type == "alumno") { // www.app.com/personas/filter/alumno
        $this->set('personas', $this->Alumno->Persona->find('all'));
    }
}

However this is returning every single Persona record, and not just the ones that have a record in the Alumno table.

How do you suggest I solve this problem? I thought that by using $this->Alumno->Persona I would only be reaching for Persona’s that are in the Alumno table.

Thanks!

Answer 1

You could use the containable behaviour and just make a find on Alumno??

$this->set('personas', $this->Alumno->find('all'));

it should retrieve the ‘Alumno’ with all the models associated to it. You could also choose which models you want to retrieve. For example, this code will retrieve all the ‘Alumno’ with its corresponding ‘Persona’

$this->set('personas', $this->Alumno->find('all',array('contain'=>array('Persona')));

An of course.. like @Paulo answered, you could manually make the join, but using “containable” is cleaner. I only make the join manually when I don’t have any other solution.

Hope this helps,