MySQL從多個記錄中選擇僅具有第一個和最后一個日期的記錄

Question

我有一個表HC_RSPI_data ：

| RADIO_TYPE |   HOP | TOWARDS | RSPI |       TP_NAME |          DATE_TIME_END | TIME_LENGTH | RLTM_min | RLTM_max |
|------------|-------|---------|------|---------------|------------------------|-------------|----------|----------|
| FlexiMetro | H3376 | RAPSANI | RSPI | ODU 1 Radio 1 | June, 08 2015 00:00:00 |       86400 |       65 |       37 |
| FlexiMetro | H3376 | RAPSANI | RSPI | ODU 1 Radio 1 | June, 09 2015 00:00:00 |       86400 |       70 |       37 |
| FlexiMetro | H3376 | RAPSANI | RSPI | ODU 1 Radio 1 | June, 08 2015 00:00:00 |       86400 |       65 |       37 |
| FlexiMetro | H3376 | RAPSANI | RSPI | ODU 2 Radio 2 | June, 10 2015 00:00:00 |       86400 |       74 |       47 |
| FlexiMetro | H3376 | RAPSANI | RSPI | ODU 2 Radio 2 | June, 09 2015 00:00:00 |       86400 |       74 |       47 |
| FlexiMetro | H3376 | RAPSANI | RSPI | ODU 2 Radio 2 | June, 08 2015 00:00:00 |       86400 |       74 |       47 |

我想獲得第一天和最后一天的記錄，例如：

| RADIO_TYPE |   HOP | TOWARDS | RSPI |       TP_NAME |          DATE_TIME_END | TIME_LENGTH | RLTM_min | RLTM_max |
|------------|-------|---------|------|---------------|------------------------|-------------|----------|----------|
| FlexiMetro | H3376 | RAPSANI | RSPI | ODU 1 Radio 1 | June, 08 2015 00:00:00 |       86400 |       65 |       37 |
| FlexiMetro | H3376 | RAPSANI | RSPI | ODU 1 Radio 1 | June, 10 2015 00:00:00 |       86400 |       70 |       37 |

| FlexiMetro | H3376 | RAPSANI | RSPI | ODU 2 Radio 2 | June, 08 2015 00:00:00 |       86400 |       74 |       47 |
| FlexiMetro | H3376 | RAPSANI | RSPI | ODU 2 Radio 2 | June, 10 2015 00:00:00 |       86400 |       74 |       47 |

要么

一條記錄，包含2個文件的開始日期和結束日期，例如： min(DATE_TIME_END)作為開始日期， max(DATE_TIME_END)作為結束日期

我怎樣才能做到這一點？ 我正在嘗試這樣的事情

SELECT DISTINCT rssi.* 
FROM HC_RSPI_data as rssi
INNER JOIN HC_RSPI_data as j
on  rssi.RADIO_TYPE     =   j.RADIO_TYPE     
and rssi.HOP            =   j.HOP            
and rssi.TOWARDS        =   j.TOWARDS        
and rssi.RSPI           =   j.RSPI           
and rssi.TP_NAME        =   j.TP_NAME
and rssi.DATE_TIME_END = j.DATE_TIME_END or j.DATE_TIME_END = DATE_ADD(rssi.DATE_TIME_END, INTERVAL 6 DAY)

有任何想法嗎？

Answer 1

一種方法是聚合數據並使用join獲取適當的值：

SELECT rssi.* 
FROM HC_RSPI_data rssi INNER JOIN
     (SELECT RADIO_TYPE, HOP, TOWARDS, RSPI, TP_NAME,
             MIN(DATE_TIME) as mindt, MAX(DATE_TIME) maxdt
      FROM HC_RSPI_data
      GROUP BY RADIO_TYPE, HOP, TOWARDS, RSPI, TP_NAME
     ) j
     ON  rssi.RADIO_TYPE     =   j.RADIO_TYPE and
         rssi.HOP            =   j.HOP and
         rssi.TOWARDS        =   j.TOWARDS and       
         rssi.RSPI           =   j.RSPI and    
         rssi.TP_NAME        =   j.TP_NAME
         rssi.DATE_TIME in (j.mindt, j.maxdt);

Answer 2

要獲得包含開始日期和結束日期的一行：

SELECT rssi.RADIO_TYPE, rssi.HOP, rssi.TOWARDS, rssi.RSPI, rssi.TP_NAME,
 MIN(rssi.DATE_TIME_END) as mindt, MAX(rssi.DATE_TIME_END) as maxdt
 FROM HC_RSPI_data as rssi 
 GROUP BY rssi.RADIO_TYPE, rssi.HOP, rssi.TOWARDS, rssi.RSPI, rssi.TP_NAME