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Update/Insert with constraint

I have two tables in SQL Server 2005: ImagesMain and ImagesNew. They have the same structure:

Expand|Select|Wrap|Line Numbers
  1. FILENAME     WIDTH    HEIGHT    LASTMODIFIED
  2. 00328.JPG    757    275     2007-05-08 09:40:25
  3. 01_806.jpg     567        423         2007-10-03 10:16:57
ImagesMain is a listing of all images on a server.

ImagesNew contains a listing of a subset of the images on the server. It contains:
-Items that exists in the main table
-Items that exists in the main table but has changed since the last update
-New items that don't exist in the main table

I'd like to update the main table in the following manner:
Expand|Select|Wrap|Line Numbers
  1. If row exists with current filename
  2.     if new date > old date
  3.         update row
  4. else
  5.     insert row
Any tips on how I could accomplish this? Cursors?

/Christian
Aug 11 '08 #1
1 1082
ck9663
2,878 Expert 2GB
Cursor is your last option.

It might be faster if you do this using 2 queries. An update query, followed by an INSERT query. If you do the INSERT first, your update query will kick-in (although no update will actually be done since LAST_MODIFIED_DATE are equal on both rows) and will take more processing time. You don't need to compare the newly inserted record since they are new in the first place.

-- CK
Aug 11 '08 #2

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