Question

我一直试图在查询中排序一天的最后一个条目，其中每个实体获得24行。我已经在this thred中阅读了与sollution相当类似的问题，但我无法将其纳入我现有的查询中。

我现有的查询：

SELECT distinct b.Udc_id as EAN, sax.attrib_01, c.channel_no, a.local_read_time, a.read, a.Status
from register_reads a, lookup_mv_channels1 c, lookup_mv_sdps b
LEFT outer JOIN s_asset@mudr2sebl sa
 ON sa.x_udc_asset_id = b.Udc_id
LEFT outer JOIN s_asset_xm@mudr2sebl sax
 ON sax.par_row_id = sa.row_id
WHERE c.Channel_id = a.channel_id
AND b.meter_id = c.meter_id
AND sax.attrib_02 = 'Y'
AND a.local_read_time >= (SYSDATE) - 1
order by b.Udc_id, a.local_read_time

这样做的结果将是例如是：

||EAN | ATTRIB_01 | channel_no | LOCAL_READ_TIME   | READ | STATUS||
||1234| ready     |     1      |09/11/2015 01:00:01|     0|  val  ||
||1234| ready     |     1      |09/11/2015 02:00:01|    10|  val  ||
||1234| ready     |     1      |        ...        |   ...|  val  ||
||1234| ready     |     1      |09/11/2015 23:59:01|    60|  val  ||
||3456| ready     |     1      |09/11/2015 01:00:01|   204|  val  ||
||3456| ready     |     1      |        ...        |   ...|  val  ||
||3456| ready     |     1      |09/11/2015 23:58:01|   400|  val  ||

我想要达到的结果是：

||EAN | ATTRIB_01 | channel_no | LOCAL_READ_TIME   | READ | STATUS||
||1234| ready     |     1      |09/11/2015 23:59:01|    60|  val  ||
||3456| ready     |     1      |09/11/2015 23:58:01|   400|  val  ||

来自@levelonehuman的反馈后更改：

SELECT  b.Udc_id as EAN, 
        c.physical_channel_no, 
        a.local_read_time, 
        a.cum_read, 
        a.validation_Status
FROM register_reads a, lookup_mv_channels1 c, lookup_mv_sdps b
    INNER JOIN (SELECT  b.Udc_id, 
                        MAX(a.LOCAL_READ_TIME) AS LOCAL_READ_TIME
               FROM    register_reads, lookup_mv_sdps b
               GROUP BY b.Udc_id) AS t2
    ON b.Udc_id = t2.Udc_id AND b.LOCAL_READ_TIME = t2.LOCAL_READ_TIME
;

Answer 1

注意：这适用于def test_export_timesheet(self): change_url = '/admin/core/timesheet/' #response contains the generated file using openpyxl response = self.client.post(change_url, {'action': 'export_xlsx', '_selected_action': [x.id for x in timesheets]}) content = response._headers.get('content-disposition')[1] start = content.find('=') + 1 end = content.find('.xlsx') content_path = (content[start:end]+'.xlsx') #Passing file like object wb = load_workbook(BytesIO(filename="'"+content_path+"'")) ws = wb.get_sheet_by_name(name="'" + content[start:end] + "'") for row in ws.iter_rows(): for cell in row: print cell.value

您需要为其他表添加其他联接，但您可以使用MSSQL和MAX(LOCAL_READ_TIME)获取最后一行：

GROUP BY EAN

SELECT EAN, ATTRIB_01, channel_no, LOCAL_READ_TIME, READ, STATUS FROM TableName t1 INNER JOIN ( SELECT EAN, MAX(LOCAL_READ_TIME) AS LOCAL_READ_TIME FROM TableName GROUP BY EAN ) AS t2 ON t1.EAN = t2.EAN AND t1.LOCAL_READ_TIME = t2.LOCAL_READ_TIME部分将选择INNER JOIN上有TableName和EAN的行 - 然后，您将加入MAX(LOCAL_READ_TIME) （同一表格）根据TableName条件选择其余数据。

实际上，这会过滤掉不符合JOIN条件的行。

每天只获得最后一行的多个条目

1 个答案: