使用 Uninon 创建 ZF2 查询“不在”子句

我想在 ZF2 中使用联合查询结果Not in。此查询的结果将返回

Query: $selectLevelTwoPointFive->combine($selectLevelAll, 'UNION');
Result: ( SELECT `assigned`.`item_id` AS `item_id` FROM `assign_items_level_twopointfive` AS `assigned` ) UNION ( SELECT `assigned`.`item_id` AS `item_id` FROM `assign_items` AS `assigned` )

现在我想在"not in"子句中使用此查询的结果。

$select = $sql->select()->from(array(
                    "items" => "cu_items"
            ))->columns(array('item_name'=>  new 'Zend'Db'Sql'Expression(" group_concat(`items`.`item_name`)") ));            
            $select->join(array(
                "ca" => "cu_areas"
            ), new Expression(" ca.area_id = items.area_id ")
             , array(
                'area_name'
            ), $selectLevelAll::JOIN_INNER);
 $select->where->addPredicate(new 'Zend'Db'Sql'Predicate'Expression('items.item_id NOT IN (?)',
                            array($selectLevelTwoPointFive)));

结果是：

SELECT group_concat(`items`.`item_name`) AS `item_name`, `ca`.`area_name` AS `area_name` FROM `cu_items` AS `items` INNER JOIN `cu_areas` AS `ca` ON ca.area_id = items.area_id WHERE `items`.`is_opted` = 'yes' AND `ca`.`is_opted` = 'yes' AND items.item_id NOT IN ((( SELECT `assigned`.`item_id` AS `item_id` FROM `assign_items_level_twopointfive` AS `assigned` ) UNION ( SELECT `assigned`.`item_id` AS `item_id` FROM `assign_items` AS `assigned` )))

它显示mysql错误： Error Code: 1064. You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'UNION ( SELECT在第 1 行分配. item_id AS item_id FROM assign_items AS受让人'

我所需的查询是：

SELECT group_concat(items.item_name) AS item_name, ca.area_name AS area_name FROM cu_items
 AS items INNER JOIN cu_areas AS ca ON ca.area_id = items.area_id
 WHERE items.is_opted = 'yes' AND ca.is_opted = 'yes' AND items.item_id NOT IN 
(
    (
        SELECT assigned.item_id AS item_id FROM assign_items_level_twopointfive AS assigned  
        UNION ( SELECT assigned.item_id AS item_id FROM assign_items AS assigned )
    )
)

实际上，当我使用 combine（） 时，它添加了圆括号（第一个查询）联合（第二个查询），但是in not我需要第一个查询联合第二个查询。

请帮忙。如果有人建议mysql更改，也可以。