Zend中的联表查询

$table_model = new Mapper对象();
$select_adapter = $table_model->getAdapter();
$Select = $select_adapter->select();
$Select -> from(array('表别名1' => '表名1'),'*');
$Select -> joinLeft(array('表别名2'=>'表名2'),'表别名2.id=表别名1.id','*');
$Select -> order('表别名1.字段desc');
$Reslut = $select_adapter-> fetchAll($Select);

public function getDbTable ($dbTable = null, $primary = null) {
if (null != $dbTable) $this->_dbObject = new Widgets_DbTable($dbTable, $primary);
if (!($this->_dbObject instanceof Zend_Db_Table_Abstract)) throw new Exception('Invalid table data gateway provided');
if ($this->_dbObject->getAdapter() instanceof Zend_Db_Adapter_Pdo_Mysql) {
	if ($this->_dbCharset) $this->_dbObject->getAdapter()->query("SET character_set_connection={$this->_dbCharset},character_set_results={$this->_dbCharset},character_set_client=binary");
}
return $this->_dbObject;
}

public function getAdapter () {
return $this->getDbTable()->getAdapter();
}