Thanks! Will try to get this working. I am using GeoAlchemy quite extensively but these more obscure functions and types are not supported...
On Aug 16, 9:14 pm, Michael Bayer <mike...@zzzcomputing.com> wrote: > On Aug 16, 2010, at 11:21 AM, bekozi wrote: > > > Is it possible to work with set-returning functions in SQLAlchemy > > without using raw SQL? For example, the PostgreSQL/PostGIS function > > ST_Dump (http://bit.ly/culek7) returns a “geometry_dump" set. Using > > ST_Dump in raw SQL goes something like: > > > SELECT > > ST_Dump(ST_Intersection(data_table1.geom,data_table2.geom)).geom AS > > geom... > > > In SQLAlchemy an attempt to construct this unsurprisingly yields an > > attribute error: > > > session.query(func.ST_Dump(functions.intersection(Data1.geom,Data2.geom).ge > > om.label('geom')) > > AttributeError: 'Function' object has no attribute 'geom' > > any SQL you want can be made available with Python expressions using > @compiles: > > from sqlalchemy import * > from sqlalchemy.sql import ColumnElement, column > > from sqlalchemy.ext.compiler import compiles > > class geom(ColumnElement): > def __init__(self, base): > self.base = base > > @compiles(geom) > def compile(expr, compiler, **kw): > return compiler.process(expr.base) + ".geom" > > data1, data2 = column('data1'), column('data2') > print select([func.ST_Dump( > geom(func.intersection(geom(data1),geom(data2))) > ).label('geom')]) > > > Curious if anyone knows a solution! A search for using set-returning > > functions in SQLAlchemy yielded no obvious solution... > > any reason you aren't using GeoAlchemy ? -- You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To post to this group, send email to sqlalch...@googlegroups.com. To unsubscribe from this group, send email to sqlalchemy+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en.
