[postgis-users] problem with multilinestring

[Dave Blasby]

Quoting Vladimir Guzmán <vguzman at maintask.com>:

> But if I try the query: "SELECT id FROM arcos WHERE startpoint(the_geom)
> ~= geometryfromtext('POINT(-74.1835602497749 4.62941345152032)',1);"
> I get no results:

You can try this with just '=' or 'equals()'.  Strk said it works with ~= on 
his machine. This is the preferred method.
You can get this to work with the index if you add a '&&' clause.

> 
> And the same problem if i try: "SELECT id FROM arcos WHERE
> x(startpoint(the_geom))::float = -74.1835602497749;"

Try this with a "::float8" instead of "::float".  You're truncating the 
geometry's x location to a float4 and postgresql is probably converting this 
to a float8 to do the '='.  The float4 and float8 version of the number will 
be slightly different.

 
dave