SQL Server-按符号在天内按分钟查找最小值

Question

Here is a snippet of the single table I am operating on. The table contains a total of 15 different symbols, spanning 3 years (CurrDate) and approximately 370 Minutes (PRMinute) in each day. I am attempting a query that will show me the lowest value for each symbol, each day and display the minute (PRMinute) that low took place.

Symbol  CurrDate    PRMinute    PROpen    PRHigh    PRLow   PRClose
SLV     2013-07-09  1           18.55     18.56     18.55   18.555
TLT     2013-07-09  1           107.45    107.45    107.45  107.45
UCO     2013-07-09  1           34.10     34.10     34.10   34.10
!COMP   2013-07-10  1           3502.11   3503.41   3502.00 3503.17
!DJI    2013-07-10  1           15298.03  15315.86  15297.07
!GSPC   2013-07-10  1           1651.56   1652.21   1651.56 1652.09 0
!RUT    2013-07-10  1           1017.69   1017.87   1017.69 1017.87 0

CREATE TABLE [dbo].[IntradayInput](
    [Symbol] [varchar](10) NULL,
    [CurrDate] [date] NULL,
    [PRMinute] [smallint] NULL,
    [PROpen] [money] NULL,
    [PRHigh] [money] NULL,
    [PRLow] [money] NULL,
    [PRClose] [money] NULL,
    [PRVol] [bigint] NULL
) ON [PRIMARY]

Answer 1

The canonical way of doing this in SQL Server is to use row_number() :

select ii.*
from (select ii.*,
             row_number() over (partition by symbol, currdate 
                                order by prlow asc end) as seqnum
      from IntradayInput ii
     ) ii
where seqnum = 1;

This assumes that prlow contains the information on the lowest value. There is no column called value .

Answer 2

This is similar to Gordon's answer, but is does not use a ranking function.

SELECT [Symbol], [CurrDate], MIN([PRLow]) AS Min_PRLow
  , (SELECT MIN([PRMinute]) FROM [IntradayInput] mi 
       WHERE mi.[Symbol]=i.[Symbol] AND mi.[CurrDate]=i.[CurrDate] 
         AND mi.PRLow=MIN(i.[PRLow])) AS PRMinute
  FROM [IntradayInput] i GROUP BY [Symbol],[CurrDate]