Question

I have the following problem:

Suppose I have a table with the following fields:
[ID]
[Start Date]
[Status Date]
[Status Description]

[ID] is not unique, and so I may have:

ID  Start Date   Status Date      Status
123 01/01/2009  01/01/2009       Start
123 01/01/2009  01/02/2009       Change
123 01/01/2009  01/03/2009       Change
123 01/01/2009  01/07/2009       Stop

What I want to do is the following: run an insert into on all the records where [Status] = ‘Start’.

When that is done, the part that I don’t know how to do is then the following: I want to update [Status Date] and [Status] to that of the final status date. I.e. what I want is:

ID  Start Date   Status Date      Status
123 01/01/2009  01/07/2009       Stop

Any suggestions?

[EDIT]

I’m using SQL Server 2008

With insert into I mean create a new table and insert into it only those records that have status “Start”, thereby achieving a table with unique IDs

Answer 1

I’m not sure if I get your right. You want the latest date and status for any ID?

That would be:

SELECT    a.ID, a.StatusDate, a.Status
FROM      Table AS a
INNER JOIN 
(
    SELECT   ID, Max(StatusDate) AS StatusDate
    FROM     Table
    GROUP BY ID
) AS b
ON        a.ID = b.ID
AND       a.StatusDate = b.StatusDate

Now, what table do you want to update with this? What do you mean by “run an insert into on all the records where [Status] = ‘Start'”? Did you create a second table and insert this date into it?

EDIT:

Okay, so I guess you want to update the data in this newly created table then?

Try this (I hope I have no syntax error in this, I don’t have an SQL server here right now to try it):

UPDATE    c
SET       c.StatusDate = a.StatusDate,
          c.Status = a.Status
FROM      NewTable AS c
INNER JOIN Table AS a
ON        c.ID = a.ID
INNER JOIN 
(
    SELECT   ID, Max(StatusDate) AS StatusDate
    FROM     Table
    GROUP BY ID
) AS b
ON        a.ID = b.ID
AND       a.StatusDate = b.StatusDate