Question

我有这个问题：

SELECT groupname, 
       Result = CASE 
                  WHEN ( thd_requesttype_dca_oms_form IS NULL 
                          OR thd_requesttype_dca_oms_form = '' ) THEN 
                  thd_requesttypeidmform
                  ELSE thd_requesttype_dca_oms_form 
                END 
FROM   zendeskticketexport 
WHERE  (groupname = 'DC Maintenance') 
        AND thd_requesttype_dca_oms_form = 'attribute_update_requests__discontinue___obsolete_request'
GROUP  BY groupname, 
          thd_requesttype_dca_oms_form, 
          thd_requesttypeidmform 
ORDER  BY groupname

我收到的结果：

groupname       Result

DC Maintenance  attribute_update_requests__discontinue___obsolete_request
DC Maintenance  attribute_update_requests__discontinue___obsolete_request
DC Maintenance  attribute_update_requests__discontinue___obsolete_request

结果是什么让我失望;我认为group by运算符应该将相同的记录组合在一起，但是group by by运算符与case运算符一起使得这些记录不会被分组。在测试这两种情况时，我看到以下查询返回0条记录：

select * from ZendeskTicketExport 

where groupName = 'DC Maintenance' and thd_requesttypeidmform = 'attribute_update_requests__discontinue___obsolete_request'

在我看来，这表明所有记录都应该组合在一起，因为case运算符只返回thd_requesttype_dca_oms_form字段的值。提前谢谢。

Answer 1

您按第三列分组。 SQL Server将创建您的组，即使该列本身不在SELECT。

中

请改为尝试：

SELECT groupname, 
       CASE
           WHEN (thd_requesttype_dca_oms_form IS NULL OR
                 thd_requesttype_dca_oms_form = '' ) THEN thd_requesttypeidmform
           ELSE thd_requesttype_dca_oms_form 
       END
FROM   zendeskticketexport 
WHERE
    groupname = 'DC Maintenance' AND
    thd_requesttype_dca_oms_form = 'attribute_update_requests__discontinue___obsolete_request'
GROUP  BY groupname,
          thd_requesttype_dca_oms_form,
       CASE
           WHEN (thd_requesttype_dca_oms_form IS NULL OR
                 thd_requesttype_dca_oms_form = '' ) THEN thd_requesttypeidmform
           ELSE thd_requesttype_dca_oms_form 
       END
ORDER  BY groupname

按操作员分组不符合预期

1 个答案: