CASE语句中的语法错误

Question

这是我的select语句。我正在试图做的是，如果一个帐户有不止一个ID，我想要的电话号码为空，否则我要手机号码= phone_number_formatted：

SELECT 
    v_returned_inventory.order_id, 
    v_live_inventory.inet_event_description, 
    v_live_inventory.event_time, 
    v_cust_phone.phone_number_formatted, 
    v_live_inventory.event_date, 
    v_returned_inventory.section_name, 
    v_returned_inventory.add_usr, 
    v_live_inventory.num_seats, 
    v_returned_inventory.acct_id, 
    v_live_inventory.class_name, 
    AT_trans_for_emailTrigger.email_addr, 
    AT_trans_for_emailTrigger.cust_name_id, 
    premclub.name_first + ' ' + premclub.name_last AS name  
FROM 
    v_returned_inventory 
INNER JOIN 
    v_live_inventory 
     ON 
LEFT(v_returned_inventory.event_name, 6) = LEFT(v_live_inventory.event_name, 6) 
AND        v_returned_inventory.orderNumber = v_live_inventory.other_info_1 INNER JOIN 
    AT_trans_for_emailTrigger 
     ON v_returned_inventory.order_id = AT_trans_for_emailTrigger.order_id 
LEFT OUTER JOIN 
    v_cust_phone 
     on v_cust_phone.acct_id = v_returned_inventory.acct_id 
LEFT OUTER JOIN 
    OPENQUERY(premclub, 'select name_first, name_last, cust_name_id from dba.v_cust_name') AS premclub 
     ON        AT_trans_for_emailTrigger.cust_name_id = premclub.cust_name_id, 
    **CASE 
     WHEN (select 
      count(cust_name_id) 
     from 
      v_cust_phone) > 1 then null 
     else v_cust_phone.phone_number_formatted 
    END** 

Answer 1

你必须在该CASE声明错误的地方，它需要在SELECT。根据你目前的情况，看起来你可能可以这样做：

SELECT v_returned_inventory.order_id, 
     v_live_inventory.inet_event_description, 
     v_live_inventory.event_time, 
     case when phone.cnt > 1 then null else v_cust_phone.phone_number_formatted end phone_number_formatted, 
     v_live_inventory.event_date, 
     v_returned_inventory.section_name, 
     v_returned_inventory.add_usr, 
     v_live_inventory.num_seats, 
     v_returned_inventory.acct_id, 
     v_live_inventory.class_name, 
     AT_trans_for_emailTrigger.email_addr, 
     AT_trans_for_emailTrigger.cust_name_id, 
     premclub.name_first + ' ' + premclub.name_last AS name 
FROM v_returned_inventory 
INNER JOIN v_live_inventory 
    ON LEFT(v_returned_inventory.event_name, 6) = LEFT(v_live_inventory.event_name, 6) 
    AND v_returned_inventory.orderNumber = v_live_inventory.other_info_1 
INNER JOIN AT_trans_for_emailTrigger 
    ON v_returned_inventory.order_id = AT_trans_for_emailTrigger.order_id 
LEFT OUTER JOIN v_cust_phone 
    on v_cust_phone.acct_id = v_returned_inventory.acct_id 
LEFT OUTER JOIN 
(
    select count(cust_name_id) cnt, cust_name_id 
    from v_cust_phone 
    group by cust_name_id 
) phone 
    on v_cust_phone.cust_name_id = phone.cust_name_id 
LEFT OUTER JOIN OPENQUERY(premclub, 'select name_first, name_last, cust_name_id from dba.v_cust_name') AS premclub 
    ON AT_trans_for_emailTrigger.cust_name_id = premclub.cust_name_id