[postgis-users] ST_Slope

[Sandro Santilli]

On Mon, Apr 02, 2012 at 08:12:14AM -0700, JamesH wrote:

> SELECT ST_AsBinary(rast), slope
> FROM (SELECT 
>         rid, rast,
> ST_Slope(ST_MapAlgebraExpr(ST_AddBand(ST_MakeEmptyRaster(10, 10, 0, 0, 0.1,
> 0.1, 0, 0, 4269), '8BUI'::text, 1, 0), '32BUI', '([rast.x] - 1) * 
> 10 + [rast.y]'), 1, '8BUI'::text) slope 
>  FROM 
>         nclheights 
>         ); AS foo
> 
> Which is returning an error of "subquery in FROM must have an alias."
> Have I used foo incorrectly?

You wrote it after the semicolon...

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