On 08/05/2011 07:32 PM, jeffrey wrote:
I have a table that looks like this: homeid city date measurement pre/post 123 san francisco 1/2/2003 1458 pre 123 san francisco NULL 1932 post 124 los angeles 2/4/2005 938 pre 124 NULL NULL 266 pre 124 los angeles 7/4/2006 777 post I'd like to write a query so that I get the following result: homeid city date measurement pre/post 123 san francisco 1/2/2003 1458 pre 123 san francisco 1/2/2003 1932 post 124 los angeles 2/4/2005 938 pre 124 los angeles 2/4/2005 266 pre 124 los angeles 7/4/2006 777 post If a city or date is null, then it will fill from other not null values with the same homeid. If given the choice, it will preferentially fill from a row where homeid AND pre/post match. But if that doesn't match, then it will still fill from the same homeid. Does anyone have ideas for this? Thanks, Jeff You need a primary key on the table to do this. Then you can do a self join and update the correct values. Sim |
