添加第二个UNION导致错误

Question

我正在处理的是正确返回的查询。

DECLARE @theItewId VARCHAR(100) = (SELECT item_id 
   FROM   ndc_attr 
   WHERE  attr_val = '00310072010'); 

SELECT nr.item_id, 
       nr.field_id, 
       nr.attr_val, 
       nr.upd_dtt, 
       nr.upd_usr, 
       nr.item_id, 
       1 AS counting, 
       nr.field_id 
FROM   ndc_attr nr 
WHERE  item_id = @theItewId 
       AND field_id IN ( 69, 144, 150, 148, 170 ) 
UNION ALL 
SELECT TOP 1 @theItewId          AS item_id, 
             418                 AS field_id, 
             nr.contract_num_val AS attr_val, 
             CURRENT_TIMESTAMP   AS upd_dtt, 
             '-1'                AS upd_usr, 
             '-1'                AS item_id, 
             '-1'                AS counting, 
             '-1'                AS field_id 
FROM   contract_ndc_brg nr 
WHERE  ndc_id = '00310072010' 
ORDER  BY upd_dtt DESC 

但是当我尝试添加另一个UNION ALL时，我收到了一个错误，并且不明白为什么。

DECLARE @theItewId VARCHAR(100) = (SELECT item_id 
   FROM   ndc_attr 
   WHERE  attr_val = '00310072010'); 

SELECT nr.item_id, 
       nr.field_id, 
       nr.attr_val, 
       nr.upd_dtt, 
       nr.upd_usr, 
       nr.item_id, 
       1 AS counting, 
       nr.field_id 
FROM   ndc_attr nr 
WHERE  item_id = @theItewId 
       AND field_id IN ( 69, 144, 150, 148, 170 ) 
UNION ALL 
SELECT TOP 1 @theItewId          AS item_id, 
             418                 AS field_id, 
             nr.contract_num_val AS attr_val, 
             CURRENT_TIMESTAMP   AS upd_dtt, 
             '-1'                AS upd_usr, 
             '-1'                AS item_id, 
             '-1'                AS counting, 
             '-1'                AS field_id 
FROM   contract_ndc_brg nr 
WHERE  ndc_id = '00310072010' 
ORDER  BY upd_dtt DESC 
UNION ALL 
SELECT TOP 1 @theItewId        AS item_id, 
             981               AS field_id, 
             nr.quote_price        AS attr_val, 
             CURRENT_TIMESTAMP AS upd_dtt, 
             '-1'              AS upd_usr, 
             '-1'              AS item_id, 
             '-1'              AS counting, 
             '-1'              AS field_id 
FROM   contract_ndc_brg nr 
WHERE  ndc_id = '00310072010' 
ORDER  BY upd_dtt DESC  

我做错了什么以及如何解决？

编辑：

  

消息156，级别15，状态1，程序USP_ENTY_ATTR_GET_BY_ATTR_VALS，第151行
  关键字＆＃39; UNION＆＃39;附近的语法不正确。

Answer 1

我认为问题是你不能在你的一个UNIONS中进行ORDER BY。您可以执行此操作，但需要将语句封装在子查询中：

SELECT * FROM
(SELECT nr.item_id, 
       nr.field_id, 
       nr.attr_val, 
       nr.upd_dtt, 
       nr.upd_usr, 
       nr.item_id, 
       1 AS counting, 
       nr.field_id 
FROM   ndc_attr nr 
WHERE  item_id = @theItewId 
       AND field_id IN ( 69, 144, 150, 148, 170 ) ) as t1
UNION ALL 
SELECT * FROM
(SELECT TOP 1 @theItewId          AS item_id, 
             418                 AS field_id, 
             nr.contract_num_val AS attr_val, 
             CURRENT_TIMESTAMP   AS upd_dtt, 
             '-1'                AS upd_usr, 
             '-1'                AS item_id, 
             '-1'                AS counting, 
             '-1'                AS field_id 
FROM   contract_ndc_brg nr 
WHERE  ndc_id = '00310072010' 
ORDER  BY upd_dtt DESC ) as t2
UNION ALL 
SELECT * FROM
(SELECT TOP 1 @theItewId        AS item_id, 
             981               AS field_id, 
             nr.quote_price        AS attr_val, 
             CURRENT_TIMESTAMP AS upd_dtt, 
             '-1'              AS upd_usr, 
             '-1'              AS item_id, 
             '-1'              AS counting, 
             '-1'              AS field_id 
FROM   contract_ndc_brg nr 
WHERE  ndc_id = '00310072010' 
ORDER  BY upd_dtt DESC ) as t3

Answer 2

ORDER BY必须只进行一次并位于查询的底部。你重复了这一行：

ORDER BY upd_dtt DESC

导致错误