Cakephp HABTM join between plugin and core application

Question

I'm having real issues doing a HABTM join between a model/table on a plugin and a model/table in my core application.

Basically my core application has a model for Items, and my plugin has a model for Purchases.

One purchase can be of many items.

I've got tables defined, all the tables in my plugin have the prefix itm_ (to denote that they're handling items)

The plugin is called itemServices.

Join table is part of the plugin and is itm_purchases_items

HABTM code is (on Item in Core):

'itemServices.Purchase' => array(
  'className' => 'itemServices.Purchase',
  'joinTable' => 'itm_purchases_items',
  'foreignKey' => 'item_id',
  'associationForeignKey' => 'purchase_id',
  'unique' => 'keepExisting',
),

and (on Purchases in Plugin):

'Item' => array(
  'className' => 'Item',
  'joinTable' => 'itm_purchases_items',
  'foreignKey' => 'purchase_id',
  'associationForeignKey' => 'item_id',
  'unique' => 'keepExisting',
 )

I'm getting SQL errors because the auto-generated query is trying to use the following notation for one side of the join

`itm_purchases` AS `itemServices`.`Purchase` 

which is creating an invalid query.

Any ideas on the correct way of doing this?

The generated SQL is (db names removed)

SELECT `itemServices`.`Purchase`.`id`,
       `itemServices`.`Purchase`.`customer_id`,
       `itemServices`.`Purchase`.`agreement_number`,
       `itemServices`.`Purchase`.`total_value`,
       `itemServices`.`Purchase`.`item_count`,
       `itemServices`.`Purchase`.`created`,
       `itemServices`.`Purchase`.`modified`,
       `purchases_items`.`purchase_id`,
       `purchases_items`.`item_id`,
       `purchases_items`.`created`,
       `purchases_items`.`modified`
FROM
        `itm_purchases` AS `itemServices`.`Purchase` 
JOIN 
        `itm_purchases_items` AS `purchases_items`
ON
       (`purchases_items`.`item_id` = 18 AND `purchases_items`.`purchase_id` = `itemServices`.`Purchase`.`id`)

Answer 1

Found the problem,

'itemServices.Purchase' => array(
  'className' => 'itemServices.Purchase',
  'joinTable' => 'itm_purchases_items',
  'foreignKey' => 'item_id',
  'associationForeignKey' => 'purchase_id',
  'unique' => 'keepExisting',
),

Should actually be:

'Purchase' => array(
  'className' => 'itemServices.Purchase',
  'joinTable' => 'itm_purchases_items',
  'foreignKey' => 'item_id',
  'associationForeignKey' => 'purchase_id',
  'unique' => 'keepExisting',
),