Question

我希望获得每组的第一个和最后一个日期。我找不到它的文档..

基本上表格如下：

select start, --timestamp
       first(open) partition by start order by asc, 
       max(high), 
       min(low), 
       last(close) partition by start order by asc
from candles_USDT_BTC
group by round(start/1800); --group by 15 min

当然第一个也是最后一个功能不存在，只是为了你们这个想法......

Answer 1

您可以使用相关子查询来查找组中具有最小/最大值的行：

SELECT start,
       (SELECT open
        FROM candles_USDT_BTC AS c2
        WHERE round(c2.start / 1800) = round(candles_USDT_BTC.start / 1800)
        ORDER BY start ASC
        LIMIT 1),
       max(high),
       min(low),
       (SELECT close
        FROM candles_USDT_BTC AS c2
        WHERE round(c2.start / 1800) = round(candles_USDT_BTC.start / 1800)
        ORDER BY start DESC
        LIMIT 1)
FROM candles_USDT_BTC
GROUP BY round(start / 1800);

Answer 2

您可以使用其他join s：

select cub.s, cub.max_high, cub.min_low, f.open, l.close
from (select round(start/1800) as s, max(high) as max_high, min(low) as min_low,
             min(start) as first_start,
             max(start) as last_start
      from candles_USDT_BTC
      group by round(start/1800)
     ) cub join
     candles_USDT_BTC f
     on f.start = cub.first_start join
     candles_USDT_BTC l
     on l.start = cub.last_start;

sqlite中的First和Last函数

2 个答案: