分組到30分鍾的間隔到最近的小時

Question

你好我想把間隔時間縮短30分鍾到最近的一小時。 我可以分組30分鍾，但我無法進行最近的小時邏輯工作。 我附上了一張快照，您可以從中了解我想要的內容。

  select SUBSTRING_INDEX(GROUP_CONCAT(CAST(price AS CHAR) ORDER BY `timestamp`), ',', 1 ) as open,
                    max(price) high,
                    min(price) low,
                    SUBSTRING_INDEX(GROUP_CONCAT(CAST(price AS CHAR) ORDER BY `timestamp` desc), ',', 1 ) as close,
                    coinrace.watch_list.symbol,
                    timestamp
                    from coinrace.watch_quote
                    join coinrace.watch_list on coinrace.watch_list.watch_id = coinrace.watch_quote.watch_id
                    where (`timestamp` between '2015-12-03' and '2015-12-10')
                    and coinrace.watch_quote.serial_number = 1
                    and coinrace.watch_quote.BuyOrSell='buy'
                    and coinrace.watch_list.symbol='MCOEUR'
                    group by  UNIX_TIMESTAMP(timestamp) div (30*60)

Answer 1

也許您應該不僅選擇timestamp ，而是選擇您要分組的值（ UNIX_TIMESTAMP(timestamp) div 1800 ），只有您還應該將其轉換回可讀的日期時間值：

from_unixtime((UNIX_TIMESTAMP(timestamp) div 1800)*1800)

所以查詢將是這樣的：

  select SUBSTRING_INDEX(GROUP_CONCAT(CAST(price AS CHAR) ORDER BY `timestamp`), ',', 1 ) as open,
                    max(price) high,
                    min(price) low,
                    SUBSTRING_INDEX(GROUP_CONCAT(CAST(price AS CHAR) ORDER BY `timestamp` desc), ',', 1 ) as close,
                    coinrace.watch_list.symbol,
                    from_unixtime((UNIX_TIMESTAMP(timestamp) div 1800)*1800) as timestamp
                    from coinrace.watch_quote
                    join coinrace.watch_list on coinrace.watch_list.watch_id = coinrace.watch_quote.watch_id
                    where (`timestamp` between '2015-12-03' and '2015-12-10')
                    and coinrace.watch_quote.serial_number = 1
                    and coinrace.watch_quote.BuyOrSell='buy'
                    and coinrace.watch_list.symbol='MCOEUR'
                    group by  UNIX_TIMESTAMP(timestamp) div (30*60)