Re: Using a CTE for an update

On 5/31/13 4:21 PM, Jeff Janes wrote:
> On Fri, May 31, 2013 at 2:37 PM, David Salisbury <salisbury@globe.gov <mailto:salisbury@globe.gov>> wrote:
>
>
>     I would think this would be possible.  I'm on 9.0.8
>
>     I have a reference between two tables, and want to populate a field in one table
>     with a value that's in the referenced table ( based on the FK reference of course ).
>
>     with row as ( select my.atmos_site_id, my.stationid from my_stations my, atmos_sites asites where
my.atmos_site_id= asites.id 
>     <http://asites.id> )
>     update atmos_sites set stationid = row.stationid where id = row.atmos_site_id;
>
>
> This ability was introduced in 9.1.
>
> "Allow WITH clauses to be attached to INSERT, UPDATE, DELETE statements (Marko Tiikkaja, Hitoshi Harada)"
>
> Also, you need a "from row" phrase on you update command.
>
> Cheers,
>
> Jeff

Thanks all.

And without trying too much ;), I'll bet there is no way to do this in SQL proper.  i.e.
I can't correlate an update with a select stmt, as in a correlated sub-query sort of way.
So for this to work I would indeed need to write a function that "hard codes" the values
within the update stmt.

-ds