sql - 前の行の値を表示する方法

Question

2 つのテーブルがあり、必要な結果を生成するクエリを作成するのに苦労しています。

表1

CREATE TABLE [Table 1](
    [ID] [int] NOT NULL,
    [Active_Status] [char](1) NOT NULL,
    [Status Change Date] [date] NOT NULL
)

INSERT INTO [Table 1] VALUES (1,'Y','2000-01-15')
INSERT INTO [Table 1] VALUES (1,'N','2003-01-20')
INSERT INTO [Table 1] VALUES (2,'N','2002-01-25')
INSERT INTO [Table 1] VALUES (2,'Y','2003-01-15')
INSERT INTO [Table 1] VALUES (2,'N','2010-01-20')
INSERT INTO [Table 1] VALUES (3,'Y','2005-01-25')
INSERT INTO [Table 1] VALUES (3,'Y','2007-01-20')
INSERT INTO [Table 1] VALUES (3,'N','2011-01-15')

表 2

CREATE TABLE [Table 2](
    [ID] [int] NOT NULL,
    [Decision] [varchar](4) NOT NULL,
    [Decision Change Date] [date] NOT NULL
)

INSERT INTO [Table 2] VALUES (1,'BUY' ,'2000-05-15')
INSERT INTO [Table 2] VALUES (1,'SELL','2010-05-20')
INSERT INTO [Table 2] VALUES (1,'SELL','2012-05-25')
INSERT INTO [Table 2] VALUES (2,'HOLD','2004-05-15')
INSERT INTO [Table 2] VALUES (2,'BUY' ,'2011-05-10')
INSERT INTO [Table 2] VALUES (3,'SELL','2008-05-15')
INSERT INTO [Table 2] VALUES (3,'BUY' ,'2011-05-25')

私の望む出力

まず、結果テーブルをIDとでソートする必要がありDecision Change Dateます。Active_Statusその後、対応するの適切な を検索する必要がありますDecision Change Date。

同様に、前の期間のActive_Statusandを表示する必要があります。Decision

Answer 1

最終的な解決策を得るためにチャットで話した後の最終編集:

DECLARE @Result TABLE
(   
  TICKR_SYMB VARCHAR (15) NOT NULL
  ,fromReviewStatus char(10)
  ,toReviewStatus char(10)
  ,ReviewStatusChangeDate DATETIME
  ,fromRestrictionStatus char(10)
  ,toRestrictionStatus char(10)
  ,RestrictionStatusChangeDate DATETIME
  ,fromCoverageStatus char(10)
  ,toCoverageStatus char(10)
  ,CoverageStatusChangeDate DATETIME
  ,fromRating VARCHAR(20)
  ,toRating VARCHAR(20)
  ,RatingChangeDate DATETIME
)

/* Rating History */
;WITH DecisionsHistory AS
(
    SELECT
        ROW_NUMBER() OVER(PARTITION BY H.TICKR_SYMB ORDER BY H.[Rating Change Date]) AS Row
        ,H.TICKR_SYMB
        ,H.[to Rating] AS toRating
        ,H.[Rating Change Date]
    FROM tblTickerRatingHistory H
)
INSERT @Result
(
    TICKR_SYMB
    ,fromRating
    ,toRating
    ,RatingChangeDate
)
SELECT
     CurrentHistory.TICKR_SYMB
    ,LastHistory.toRating AS fromRating
    ,CurrentHistory.toRating
    ,CurrentHistory.[Rating Change Date]
FROM DecisionsHistory CurrentHistory
LEFT JOIN DecisionsHistory LastHistory
    ON LastHistory.Row = (CurrentHistory.Row - 1)
    AND LastHistory.TICKR_SYMB = CurrentHistory.TICKR_SYMB

/* ReviewStatus */
;WITH ReviewStatusHistory AS 
(
  SELECT
    ROW_NUMBER() OVER(PARTITION BY R.TICKR_SYMB, R.RatingChangeDate ORDER BY H.ReviewStatusChangeDate DESC) AS Row
    ,R.TICKR_SYMB 
    ,R.RatingChangeDate
    ,H.ReviewStatus AS ToReviewStatus
    ,H.ReviewStatusChangeDate
  FROM @Result R
  LEFT JOIN tblTickerStatusHistory H
    ON H.TICKR_SYMB = R.TICKR_SYMB
    AND H.ReviewStatusChangeDate < R.RatingChangeDate
)
UPDATE R
SET 
  fromReviewStatus = LastActiveHistory.toReviewStatus
  ,toReviewStatus = CurrentActiveHistory.toReviewStatus
  ,ReviewStatusChangeDate = CurrentActiveHistory.ReviewStatusChangeDate
FROM @Result R
LEFT JOIN ReviewStatusHistory CurrentActiveHistory
  ON CurrentActiveHistory.TICKR_SYMB = R.TICKR_SYMB
  AND CurrentActiveHistory.RatingChangeDate = R.RatingChangeDate
  AND CurrentActiveHistory.Row = 1
LEFT JOIN ReviewStatusHistory LastActiveHistory
    ON LastActiveHistory.TICKR_SYMB = R.TICKR_SYMB
    AND LastActiveHistory.RatingChangeDate = R.RatingChangeDate
    AND LastActiveHistory.Row = 2

/* CoverageStatus */
;WITH CoverageStatusHistory AS 
(
  SELECT
    ROW_NUMBER() OVER(PARTITION BY R.TICKR_SYMB, R.RatingChangeDate ORDER BY H.CoverageStatusChangeDate DESC) AS Row
    ,R.TICKR_SYMB 
    ,R.RatingChangeDate
    ,H.CoverageStatus AS ToCoverageStatus
    ,H.CoverageStatusChangeDate
  FROM @Result R
  LEFT JOIN tblTickerStatusHistory H
    ON H.TICKR_SYMB = R.TICKR_SYMB
    AND H.CoverageStatusChangeDate < R.RatingChangeDate
)
UPDATE R
SET 
  fromCoverageStatus = LastActiveHistory.toCoverageStatus
  ,toCoverageStatus = CurrentActiveHistory.toCoverageStatus
  ,CoverageStatusChangeDate = CurrentActiveHistory.CoverageStatusChangeDate
FROM @Result R
LEFT JOIN CoverageStatusHistory CurrentActiveHistory
  ON CurrentActiveHistory.TICKR_SYMB = R.TICKR_SYMB
  AND CurrentActiveHistory.RatingChangeDate = R.RatingChangeDate
  AND CurrentActiveHistory.Row = 1
LEFT JOIN CoverageStatusHistory LastActiveHistory
    ON LastActiveHistory.TICKR_SYMB = R.TICKR_SYMB
    AND LastActiveHistory.RatingChangeDate = R.RatingChangeDate
    AND LastActiveHistory.Row = 2

 /*RestrictionStatus */
;WITH RestrictionStatusHistory AS 
(
  SELECT
    ROW_NUMBER() OVER(PARTITION BY R.TICKR_SYMB, R.RatingChangeDate ORDER BY H.RestrictionStatusChangeDate DESC) AS Row
    ,R.TICKR_SYMB 
    ,R.RatingChangeDate
    ,H.RestrictionStatus AS ToRestrictionStatus
    ,H.RestrictionStatusChangeDate
  FROM @Result R
  LEFT JOIN tblTickerStatusHistory H
    ON H.TICKR_SYMB = R.TICKR_SYMB
    AND H.RestrictionStatusChangeDate < R.RatingChangeDate
)
UPDATE R
SET 
  fromRestrictionStatus = LastActiveHistory.toRestrictionStatus
  ,toRestrictionStatus = CurrentActiveHistory.toRestrictionStatus
  ,RestrictionStatusChangeDate = CurrentActiveHistory.RestrictionStatusChangeDate
FROM @Result R
LEFT JOIN RestrictionStatusHistory CurrentActiveHistory
  ON CurrentActiveHistory.TICKR_SYMB = R.TICKR_SYMB
  AND CurrentActiveHistory.RatingChangeDate = R.RatingChangeDate
  AND CurrentActiveHistory.Row = 1
LEFT JOIN RestrictionStatusHistory LastActiveHistory
    ON LastActiveHistory.TICKR_SYMB = R.TICKR_SYMB
    AND LastActiveHistory.RatingChangeDate = R.RatingChangeDate
    AND LastActiveHistory.Row = 2


SELECT
  R1.TICKR_SYMB
  ,R1.fromCoverageStatus
  ,R1.toCoverageStatus
  ,R1.CoverageStatusChangeDate
  ,R1.fromReviewStatus
  ,R1.toReviewStatus
  ,R1.ReviewStatusChangeDate
  ,R1.fromRestrictionStatus
  ,R1.toRestrictionStatus
  ,R1.RestrictionStatusChangeDate
  ,R1.fromRating
  ,R1.toRating
  ,R1.RatingChangeDate
FROM @Result R1
ORDER BY TICKR_SYMB, RatingChangeDate 

Answer 2

ここから始めるべきことがあります。

    create table t1 (
  id int, act char(1), scd date
  )

create table t2 (
  id int, decs varchar(4), dcd date
  )

insert into t1 values

( 1, 'y', '20000115'),
( 1, 'n', '20030120'),
( 2, 'n', '20020125'),
( 2, 'y', '20030115'),
( 2, 'n', '20100120'),
( 3,'y','20050125'),
( 3,'y','20070120'),
( 3,'n','20110115')

insert into t2 values

(1,'buy','20000515' ),
(1,'sell', '20100520' ),
(1,'sell', '20120525' ),
(2,'hold', '20040515'),
(2,'buy', '20110510' ),
(3,'sell', '20080515'),
(3,'buy','20110525' )

with decisions as (

  select row_number() over (partition by id order by dcd) as rn,
   id, decs, dcd from t2
  ),
activities as 
(
  select row_number() over (partition by id order by scd) as rn,
  id, act, scd from t1
  )

select dec_to.id, x.from_act, x.to_act, x.scd, x.from_act, x.to_act, x.scd as scd, dec_from.decs as from_dec, dec_to.decs as to_dec, dec_to.dcd from decisions dec_from
right outer join decisions dec_to on dec_from.id = dec_to.id and 
dec_to.rn = dec_from.rn + 1
outer apply (
  select top 1 act_to.id, act_from.act as from_act, act_to.act as to_act, act_to.scd
  from activities act_to
  left outer join activities as act_from
  on act_from.id = act_to.id and act_from.rn = act_to.rn - 1
  where act_to.id = dec_to.id and act_to.scd <= dec_to.dcd
  order by act_to.scd desc
) x  

order by dec_to.id, dec_to.rn

はい、醜いです。適切なインデックスがないと、大規模なデータセットではうまく機能しない可能性があります。ただし、要件はあいまいであり、どの行がどこに行くかについて使用するルールはあまり意味がありません。

ここでの前提は、決定日以前の「最新」の活動変更行が必要であるということです。これはうまく機能し、以下を生成します

ID  FROM_ACT    TO_ACT  SCD     FROM_DEC    TO_DEC  DCD
1           y   2000-01-15          buy 2000-05-15
1   y       n   2003-01-20  buy     sell    2010-05-20
1   y       n   2003-01-20  sell        sell    2012-05-25
2   n       y   2003-01-15          hold    2004-05-15  
2   y       n   2010-01-20  hold        buy 2011-05-10
3   y       y   2007-01-20          sell    2008-05-15
3   y       n   2011-01-15  sell        buy 2011-05-25

SQLFiddleで遊ぶことができます