需要幫助編寫Teradata SQL來驗證由多個SCD type2表組合的多個日期範圍

我想驗證從多個SCD type2表派生的視圖。所以，我必須根據兩個（或更多）表中可用日期的組合創建日期範圍。看下面的例子。需要幫助編寫Teradata SQL來驗證由多個SCD type2表組合的多個日期範圍

表1：

hid  h1name   h1_strt_dttm     h1_end_dttm 

5  value5   2/17/2008 18:19:50 2/16/2009 23:59:59:59 

5  value5-upd1  2/17/2009 00:00:00 4/11/2011 23:59:59 

5  value5-upd2  4/12/2011 00:00:00 3/5/2012 23:59:59 

5  value5-upd3  3/6/2012 00:00:00 11/11/2012 23:59:59 

5  value5-upd4  11/12/2012 00:00:00 12/31/9999 23:59:59

表2：

hid h2name  h2_strt_dttm   h2_end_dttm 

5 name5   3/7/2008 8:14:44  7/17/2010 23:59:59 

5 name5-upd1  7/18/2010 0:00:00  1/1/2011 23:59:59 

5 name5-upd2  1/2/2011 0:00:00  3/5/2013 23:59:59 

5 name5-upd3  3/6/2013 0:00:00  12/31/9999 23:59:59

結果集：

id strt_dttm    end_dttm   h1name  h2name 

    5 2/17/2008 18:19:50 3/7/2008 8:14:43  value5  null 

    5 3/7/2008 8:14:44  2/16/2009 23:59:59 value5  name5 

    5 2/17/2009 00:00:00 7/17/2010 23:59:59 value5-upd1 name5 

    5 7/18/2010 00:00:00 1/1/2011 23:59:59  value5-upd1 name5-upd1 

    5 1/2/2011 00:00:00  4/11/2011 23:59:59 value5-upd1 name5-upd2 

    5 4/12/2011 00:00:00 3/5/2012 23:59:59  value5-upd2 name5-upd2 

    5 3/6/2012 00:00:00  11/11/2012 23:59:59 value5-upd3 name5-upd2 

    5 11/12/2012 00:00:00 3/5/2013 23:59:59  value5-upd4 name5-upd2 

    5 3/6/2013 00:00:00  1/1/9999 00:00:00  value5-upd4 name5-upd3

步驟來實現這一點：我的方法：

1）將兩個（或更多）表中的所有可用STRT_DTTM字段值聯合起來。

2）分發/重新創建從在步驟1中可用的上述日期的日期範圍（如開始日期和日期和結束日期）

3）然後嘗試找出CDC字段（h1name & h2name）與新創建的日期範圍並將其放入結果集中。查詢：

第1步：

sel h1.hid hid , h1_strt_dttm dtm 

from HIST1_DAR h1 

union 

sel h2.hid hid ,h2_strt_dttm dtm 

from HIST2_DAR h2

第2步：

/*************** Step 2 ********************/ 

WITH ALL_DATE_CTE (hid,dttm,strt_dttm,end_dttm) AS (

sel hid, 

dtm+INTERVAL '0.000001' SECOND as dttm , 

dttm-INTERVAL '0.000001' SECOND as strt_dttm, 

coalesce(min(strt_dttm-INTERVAL '1' SECOND) over (partition by hid 

order by dttm ROWS BETWEEN 1 following 

AND 1 following), cast('9999-01-01 00:00:00.000000' as timestamp(6))) as end_dttm 

from 

(

/*************** Step 1 ********************/ 

sel h1.hid hid , h1_strt_dttm dtm 

from DBNAME.HIST1_DAR h1 

union 

sel h2.hid hid ,h2_strt_dttm dtm 

from DBNAME.HIST2_DAR h2 

/*************** Step 1 ********************/ ) a 

order by 1,2 ) 

/**************** Step 2********************/

第3步：

/**************** Step 3********************/ 

sel 

h1.hid id, 

cte.strt_dttm, 

cte.end_dttm, 

h1.h1name, 

h1_strt_dttm , h1_end_dttm, 

h2.h2name, 

h2_strt_dttm,h2_end_dttm 

from DBNAME.HIST1_DAR h1 

inner join ALL_DATE_CTE cte 

on h1.hid = cte.hid 

and cte.dttm between h1_strt_dttm and h1_end_dttm 

inner join DBNAME.HIST2_DAR h2 

on cte.hid = h2.hid 

and cte.dttm between h2_strt_dttm and h2_end_dttm 

where h1.hid = 5; 

/**************** Step 3********************/

現在的問題是與第2步：我不能在子查詢中以及在CTE中使用順序。沒有訂購開始日期，我無法正確列出日期範圍。

任何人都可以請指導我的解決方案或其他簡單的方法。請注意，因爲我是QA，所以我沒有在大多數數據庫上創建表訪問權限。所以，使用select的任何建議都會更明顯。我已經包含了我用於創建表格的DDL & DML。

create table DBNAME. hist1_dar (hid integer , h1name varchar(20), h1_strt_dttm timestamp(6), h1_end_dttm timestamp(6)); 

create table DBNAME. hist2_dar (hid integer , h2name varchar(20), h2_strt_dttm timestamp(6), h2_end_dttm timestamp(6)); 

ins DBNAME. hist1_dar (1, 'value1' , '1987-07-02 08:30:00.000000', '1989-12-02 23:59:59.000000'); 

ins DBNAME. hist1_dar (2, 'value2' , '1997-09-12 05:20:10.000000' , '1999-12-12 23:59:59.000000'); 

ins DBNAME. hist1_dar (3, 'value3' , '2000-06-30 07:10:50.000000', '2001-02-10 23:59:59.000000'); 

ins DBNAME. hist1_dar (4, 'value4' , '2006-05-23 23:32:13.000000', '2007-07-03 23:59:59.000000'); 

ins DBNAME. hist1_dar (5, 'value5' , '2009-02-17 18:19:50.000000', '2011-04-11 11:09:59.000000'); 


ins DBNAME. hist1_dar (1, 'value1-upd1' , '1990-01-01 01:01:01.000000', '9999-12-31 23:59:59.000000'); 

ins DBNAME. hist1_dar (2, 'value2-upd1' , '2000-01-01 01:01:01.000000' , '9999-12-31 23:59:59.000000'); 

ins DBNAME. hist1_dar (3, 'value3-upd1' , '2001-02-11 01:01:01.000000', '2002-07-12 23:59:59.000000'); 

ins DBNAME. hist1_dar (3, 'value3-upd2' , '2002-07-13 01:01:01.000000', '9999-12-31 23:59:59.000000'); 

ins DBNAME. hist1_dar (4, 'value4-upd1' , '2007-07-03 01:01:01.000000' , '2007-10-17 23:59:59.000000'); 

ins DBNAME. hist1_dar (4, 'value4-upd2' , '2007-10-18 01:01:01.000000' , '2007-12-23 23:59:59.000000'); 

ins DBNAME. hist1_dar (4, 'value4-upd3' , '2007-12-24 01:01:01.000000' , '9999-12-31 23:59:59.000000'); 

ins DBNAME. hist1_dar (5, 'value5-upd1' , '2009-02-17 01:01:01.000000', '2011-04-11 23:59:59.000000'); 

ins DBNAME. hist1_dar (5, 'value5-upd2' , '2011-04-11 01:01:01.000000', '2012-03-05 23:59:59.000000'); 

ins DBNAME. hist1_dar (5, 'value5-upd3' , '2012-03-05 01:01:01.000000', '2012-11-11 23:59:59.000000' ); 

ins DBNAME. hist1_dar (5, 'value5-upd4' , '2012-11-12 01:01:01.000000' , '9999-12-31 23:59:59.000000'); 


ins DBNAME. hist2_dar (1, 'name1' , '1988-08-12 18:20:10.000000', '1990-03-02 23:59:59.000000'); 

ins DBNAME. hist2_dar (2, 'name2' , '1993-05-19 15:12:30.000000', '1999-11-01 23:59:59.000000'); 

ins DBNAME. hist2_dar (3, 'name3' , '2002-09-20 17:19:57.000000', '2003-04-10 23:59:59.000000'); 

ins DBNAME. hist2_dar (4, 'name4' , '2004-04-18 13:38:23.000000' , '2005-07-28 23:59:59.000000'); 

ins DBNAME. hist2_dar (5, 'name5' , '2008-03-07 08:14:44.000000', '2010-07-17 23:59:59.000000'); 



ins DBNAME. hist2_dar (1, 'name1-upd1' , '1990-03-03 01:01:01.000000', '9999-12-31 23:59:59.000000'); 

ins DBNAME. hist2_dar (2, 'name2-upd1' , '1999-11-02 01:01:01.000000', '9999-12-31 23:59:59.000000'); 

ins DBNAME. hist2_dar (3, 'name3-upd1' , '2003-04-11 01:01:01.000000' , '9999-12-31 23:59:59.000000'); 

ins DBNAME. hist2_dar (4, 'name4-upd1' , '2005-07-28 21:28:56.000000' , '2008-08-19 23:59:59.000000'); 

ins DBNAME. hist2_dar (4, 'name4-upd2' , '2008-08-20 01:01:01.000000' , '2007-12-23 23:59:59.000000'); 

ins DBNAME. hist2_dar (5, 'name5-upd1' , '2010-07-18 01:01:01.000000', '2011-01-01 23:59:59.000000'); 

ins DBNAME. hist2_dar (5, 'name5-upd2' , '2011-01-02 01:01:01.000000', '2013-03-05 23:59:59.000000'); 

ins DBNAME. hist2_dar (5, 'name5-upd3' , '2013-03-06 01:01:01.000000', '9999-12-31 23:59:59.000000' );

來源

2015-08-28 user3534583

什麼是你的Teradata版本？ – dnoeth

VERSION \t 14.10.03.04 – user3534583

你的INSERT語句中不匹配您的例子。

如果你的第2步中返回正確的數據，你可以簡單地添加一個LAST_VALUE：

WITH cte (
    hid 
    ,strt_dttm 
    ,end_dttm 
    ,h1name 
    ,h2name 
    ) 
AS (
    SELECT hid 
     ,dttm 
     ,coalesce(min(dttm - INTERVAL '1' SECOND) OVER (
       PARTITION BY hid ORDER BY dttm ROWS BETWEEN 1 following 
         AND 1 following 
       ), TIMESTAMP '9999-01-01 00:00:00') AS end_dttm 
     ,h1name 
     ,h2name 
    FROM (
     /*************** Step 1 ********************/ 
     SELECT h1.hid hid 
      ,h1_strt_dttm dttm 
      ,h1name 
      ,cast(NULL AS VARCHAR(20)) AS h2name 
     FROM HIST1_DAR h1 

     UNION ALL 

     SELECT h2.hid hid 
      ,h2_strt_dttm dttm 
      ,cast(NULL AS VARCHAR(20)) 
      ,h2name 
     FROM HIST2_DAR h2 
      /*************** Step 1 ********************/ 
     ) a 
     --order by 1,2 
    ) 
SELECT hid 
    ,strt_dttm 
    ,end_dttm 
    ,last_value(h1name ignore nulls) OVER (
     PARTITION BY hid ORDER BY strt_dttm 
     ) 
    ,last_value(h2name ignore nulls) OVER (
     PARTITION BY hid ORDER BY strt_dttm 
     ) 
FROM cte

來源

2015-08-31 17:36:30 dnoeth

需要幫助編寫Teradata SQL來驗證由多個SCD type2表組合的多個日期範圍

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