[TYPO3-mvc] Lost again or my problem with mapped tx_dam

[Sebastian Fischer]

Hi everyone,

i need to fetch images out of dam and that's why puzzeled arount with it.

My results so fare:
- My mapping in TS
	persistence {
		classes {
			Tx_MyExt_Domain_Model_Dam {
				mapping {
					tableName = tx_dam
				}
			}
			Tx_MyExt_Domain_Model_DamCategory {
				mapping {
					tableName = tx_dam_cat
				}
			}
		}
	}
- a simple model Tx_MyExt_Domain_Model_Dam with category attribute
	/**
	 * @var 
Tx_Extbase_Persistence_ObjectStorage<Tx_MyExt_Domain_Model_DamCategory>
	 */
	protected $category;

	/**
	 * Setter for category
	 *
	 * @param 
Tx_Extbase_Persistence_ObjectStorage<Tx_MyExt_Domain_Model_DamCategory>
	 * @return void
	 */
	public function setCategory(Tx_Extbase_Persistence_ObjectStorage 
$category) {
		$this->category = $category;
	}

	/**
	 * Getter for category
	 *
	 * @return 
Tx_Extbase_Persistence_ObjectStorage<Tx_MyExt_Domain_Model_DamCategory>
	 */
	public function getCategory() {
		return $this->category;
	}

- and a repository with following function:
	/**
	 * Fetch images that contain given categories
	 *
	 * @param	string
	 * @return	array
	 */
	public function findByCategory($categoryUidList) {
		$query = $this->createQuery();
		$query->getQuerySettings()->setRespectStoragePage(FALSE);

		$uids = explode(',', $categoryUidList);
		$query->matching($query->equals('category', $uids));

		return $query->execute();
	}

As you know category is a foreign table with mm table. But my query ends 
without result and i can't locate the problem. Is anyone around that has 
a solution?

Greetings
Sebastian