table design

I am a novice with SQL, so please don't hold it against me.

I have a text file that I import into SQL.   (easy enough)
There are not many fields (maybe 20)
THere are is One field named PO which can be in multiple times.  Another
field name STYLE that can also have duplicate rcords.   BUT   The same PO
number with the same STYLE number will not duplicate.
But I will have another text file to import that would update info for the
record that has the same PO and Style.   How would I do that?
ANy place on teh Internet where I might be able to figure this out?

Its a one to many relationship for PO and STYLE.

-------
Regards ,
C#, VB.NET , SQL SERVER , UML , DESIGN Patterns Interview question book
http://www.geocities.com/dotnetinterviews/
My Interview Blog
http://spaces.msn.com/members/dotnetinterviews/

On Fri, 28 Oct 2005 13:37:11 -0700, Johnfli wrote:

>I am a novice with SQL, so please don't hold it against me.
>
>I have a text file that I import into SQL.   (easy enough)
>There are not many fields (maybe 20)
>THere are is One field named PO which can be in multiple times.  Another
>field name STYLE that can also have duplicate rcords.   BUT   The same PO
>number with the same STYLE number will not duplicate.
>But I will have another text file to import that would update info for the
>record that has the same PO and Style.   How would I do that?
>ANy place on teh Internet where I might be able to figure this out?
>

Hi Johnfli,

Import your second text file to a staging table. Then merge it onto the
main table with the following two commands:

UPDATE MainTable
SET    Column1 = StagingTable.Column1,
Column2 = StagingTable.Column2,
-- repeat for all columns except PO and STYLE
FROM   MainTable
JOIN   StagingTable
ON     StagingTable.PO = MainTable.PO
AND    StagingTable.STYLE = MainTable.STYLE

INSERT INTO MainTable (PO, STYLE, Column1, Column2, ...)
SELECT PO, STYLE, Column1, Column2, ...
FROM   StagingTable
WHERE NOT EXISTS
(SELECT *
FROM   MainTable
WHERE  MainTable.PO = StagingTable.PO
AND    MainTable.STYLE = StagingTable.STYLE)

Best, Hugo
--

(Remove _NO_ and _SPAM_ to get my e-mail address)