Deriving historical data from status changes

  • Ok, I am having a complete brain fade today. I have a table which records a status for people. A record is written with a code of 1 when a new status begins. A record is written when a status is terminated/released. The data looks like this:

    LAST_NAME STATUS_CODE_DATE ID_SET_STATUS_TYPE

    ------------------------------- ----------------------- ------------------

    Graham2002-10-07 00:00:00.0001

    Graham2003-02-04 00:00:00.0003

    Graham2003-05-23 00:00:00.0001

    Graham2004-02-06 00:00:00.0003

    Graham2004-02-10 00:00:00.0001

    Graham2004-04-23 00:00:00.0003

    I need to write code to display the data above in three rows with each row having the start and end dates of the status. Example of what I need to see:

    LAST_NAME STATUS_CODE START_DATE STATUS_EXIT_CODE END_DATE

    --------- ----------- ----------------------- ---------------- -----------------------

    Graham 1 2002-10-07 00:00:00.000 3 2003-02-04 00:00:00.000

    Graham 1 2003-05-23 00:00:00.000 3 2004-02-06 00:00:00.000

    Graham 1 2004-02-10 00:00:00.000 3 2004-04-23 00:00:00.000

    Can someone please help me sort this out quickly? I have done this 1000 times if I have done it once BUT TODAY !?#@?$^@! I am at a loss. Of course, I am under the gun so the stress is cutting off the blood flow to my brain. 😉

    Thanks in advance.

  • This should get you close. You are going to have to add something in the column that has the query to identify a person like...

    And A.CustomerID = B.CustomerID

    Right Now I am just joing by Last Name.

    Create Table #tmp

    (LAST_NAME Varchar(50),

    STATUS_CODE_DATE DateTime,

    ID_SET_STATUS_TYPE Int)

    Insert Into #tmp Values('Graham', '2002-10-07 00:00:00.000', 1)

    Insert Into #tmp Values('Graham', '2003-02-04 00:00:00.000' , 3)

    Insert Into #tmp Values('Graham' , '2003-05-23 00:00:00.000', 1)

    Insert Into #tmp Values('Graham', '2004-02-06 00:00:00.000', 3)

    Insert Into #tmp Values('Graham', '2004-02-10 00:00:00.000', 1)

    Insert Into #tmp Values('Graham' , '2004-04-23 00:00:00.000', 3)

    Insert Into #tmp Values('Simmons', '2002-10-07 00:00:00.000', 1)

    Insert Into #tmp Values('Simmons' , '2004-04-23 00:00:00.000', 3)

    Select LAST_NAME,

    1,

    STATUS_CODE_DATE ,

    3,

    (Select Min(STATUS_CODE_DATE) FROM #tmp A

    Where A.ID_SET_STATUS_TYPE = 3 and

    A.STATUS_CODE_DATE > B.STATUS_CODE_DATE AND

    A.LAST_NAME = B.LAST_NAME)

    from #tmp B

    Where B.ID_SET_STATUS_TYPE = 1

    Drop Table #tmp

  • Thank you. That will get me moving forward.

  • Something along this line :

    SELECT

    t.LAST_NAME,

    t.ID_SET_STATUS_TYPE AS STATUS_CODE,

    t.STATUS_CODE_DATE AS START_DATE,

    (

    SELECT Top 1 t1.ID_SET_STATUS_TYPE

    FROM theHistoryTable t1

    WHERE t1.LAST_NAME=t.LAST_NAME And t1.STATUS_CODE_DATE>t.STATUS_CODE_DATE

    ORDER BY t1.STATUS_CODE_DATE ASC

    ) AS STATUS_EXIT_CODE,

    (

    SELECT Top 1 t1.STATUS_CODE_DATE

    FROM theHistoryTable t1

    WHERE t1.LAST_NAME=t.LAST_NAME And t1.STATUS_CODE_DATE>t.STATUS_CODE_DATE

    ORDER BY t1.STATUS_CODE_DATE ASC

    ) AS END_DATE

    FROM theHistoryTable t

    WHERE t.ID_SET_STATUS_TYPE = 1

    devloping robust and performant databaseapplications with Microsoft SQL-Server

  • SELECT ...

    FROM table1 t1

    LEFT JOIN table1 t2 ON t2.key = t1.key AND t2.ID_SET_STATUS_TYPE = 3

    WHERE t1.ID_SET_STATUS_TYPE = 1;

    Need to identify the key column(s) for the table, but essentially - you need to join the table to itself including in the join only the final status and filter to the initial status.

    Another option:

    ;WITH cteInitial (LastName, StatusDate, StatusCode)

    AS (SELECT Last_Name

    ,STATUS_CODE_DATE

    ,ID_SET_STATUS_TYPE

    FROM table1

    WHERE ID_SET_STATUS_TYPE = 1)

    ,cteFinal (LastName, StatusDate, StatusCode)

    ,STATUS_CODE_DATE

    ,ID_SET_STATUS_TYPE

    FROM table1

    WHERE ID_SET_STATUS_TYPE = 3)

    SELECT ...

    FROM cteInitial i

    JOIN cteFinal ON i.LastName = f.LastName;

    Jeffrey Williams
    “We are all faced with a series of great opportunities brilliantly disguised as impossible situations.”

    ― Charles R. Swindoll

    How to post questions to get better answers faster
    Managing Transaction Logs

Viewing 5 posts - 1 through 4 (of 4 total)

You must be logged in to reply to this topic. Login to reply