Thanks, will test it tomorrow.
Examples with long/lat inserts, extracts and distance comparisons would
also be handy for the book.
On Sun, Dec 23, 2012 at 4:50 AM, Massimo Di Pierro <
massimo.dipie...@gmail.com> wrote:
> I made some changes to the DAL geo APIs. This is an experimental feature
> so we are allowed to make changes. Anyway, the changes should be backward
> compatible. The only issue is that I am documenting the geodal api in the
> book and I would not want to change them later.
>
> Can you please check them:
>
> The DAL supports geographical APIs using PostGIS (for PostgreSQL),
> spatialite (for SQLite), and MSSQL and Spatial Extensions.
>
> DAL provides geometry and geography fields types and the following
> functions:
>
> st_asgeojson (PostGIS only)
> st_astext
> st_contained
> st_contains
> st_distance
> st_equals
> st_intersects
> st_overlaps
> st_simplify (PostGIS only)
> st_touches
> st_within
>
> examples:
>
> >>> from gluon.dal import DAL, Field, geoPoint, geoLine, geoPolygon
> >>> db = DAL("mssql://user:pass@host:db")
> >>> sp = db.define_table('spatial',Field('loc','geometry()'))
>
> >>> sp.insert(loc=geoPoint(1,1))
> >>> sp.insert(loc=geoLine((100,100),(20,180),(180,180)))
> >>> sp.insert(loc=geoPolygon((0,0),(150,0),(150,150),(0,150),(0,0)))
>
>
> >>> print db(sp.id>0).select()
> spatial.id,spatial.loc
> 1, POINT (1 2)"
> 2, LINESTRING (100 100, 20 180, 180 180)
> 3, POLYGON ((0 0, 150 0, 150 150, 0 150, 0 0))
>
> >>> query = sp.loc.st_intersects(geoLine((20,120),(60,160)))
> >>> query =
> sp.loc.st_overlaps(geoPolygon((1,1),(11,1),(11,11),(11,1),(1,1)))
> >>> query = sp.loc.st_contains(geoPoint(1,1))
> >>> print db(query).select(sp.id,sp.loc)
> spatial.id,spatial.loc
> 3,"POLYGNON ((0 0, 150 0, 150 150, 0 150, 0 0))"
>
> >>> dist = sp.loc.st_distance(geoPoint(-1,2)).with_alias('dist')
> >>> print db(sp.id>0).select(sp.id, dist)
> spatial.id, dist
> 1 2.0
> 2 140.714249456
> 3 1.0
>
> --
>
>
>
>
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