Cakephp 2.0: complex find query - php

Question

I'm trying to pull some info out of two tables linked by the hasMany and belongsTo associations.
requisitions hasMany locations and locations belongsTo requisitions
TABLE `requisitions` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`user_id` int(11) NOT NULL,
`fecha_generacion` date NOT NULL,
`solicitado_a` varchar(60) NOT NULL,
`proyecto` varchar(150) NOT NULL,
`obra_no` varchar(11) NOT NULL,
`observaciones` text NOT NULL,
PRIMARY KEY (`id`)
)
and
TABLE `locations` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`requisition_id` int(11) NOT NULL,
`fecha` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
`name` enum('pendiente','tecnico','existencia','cotizando','generar_o','archivada')
NOT NULL DEFAULT 'pendiente',
`image_path` varchar(150) NOT NULL DEFAULT 'estado0.png',
`note` text NOT NULL,
PRIMARY KEY (`id`)
)
Requisition goes from one Location to another and I need to keep track of its current Location looking by a given Location as 'pendiente','tecnico'...
So I need to generate a list with the last Location for each Requisition and then filter that list by the Location.name
I believe the only way to do this is with a query around another query, so I'm trying to understand cakephp syntax with more simple queries first.
I was trying to search for the last 'pendiente' Location with the next code from my RequisitionsController.
$lastPendiente = $this->Requisition->Location->find('all', array(
'conditions' => array('Location.name' => 'pendiente'),
'fields' => array('MAX(Location.id) AS olderLocation', 'Location.requisition_id'),
'group' => 'Requisition.id',
));
I have the query
SELECT MAX(`Location`.`id`) AS olderLocation, `Location`.`requisition_id` FROM `petrofil_demo`.`locations` AS `Location` LEFT JOIN `petrofil_demo`.`requisitions` AS `Requisition` ON (`Location`.`requisition_id` = `Requisition`.`id`) WHERE `Location`.`name` = 'pendiente' GROUP BY `Requisition`.`id`
output...
array(
(int) 0 => array(
(int) 0 => array(
'olderLocation' => '22'
),
'Location' => array(
'requisition_id' => '29'
)
),
(int) 1 => array(
(int) 0 => array(
'olderLocation' => '5'
),
'Location' => array(
'requisition_id' => '30'
)
),
(int) 2 => array(
(int) 0 => array(
'olderLocation' => '13'
),
'Location' => array(
'requisition_id' => '31'
)
)
)
...which is great because those are exactly the last requisitions with a 'pendiente' location but here comes the second query or the condition where I'm clueless. I need to be sure my requisition last state was 'pendiente' and not another possible locations. For example my requisition_id =>30 last location is really 'tecnico' so I need to find a way to exclude it from showing on my results.

Answer 1

You could quit the condition from the query, put the 'name' column in the 'fields' and add an order by sentence:
$lastPendiente = $this->Requisition->Location->find('all', array(
'fields' => array('MAX(Location.id) AS olderLocation', 'Location.requisition_id', 'name'),
'group' => 'Requisition.id',
'order' => 'fecha DESC'
));
This way you only get the last status from the Location table. Then, you could iterate the results, filtering by the 'name' column and deleting those whit a 'name' diferent from 'pendiente':
foreach($lastPendiente as $k => $location){
if($location['Location']['name'] != 'pendiente'){
unset($lastPendiente[$k]);
}