postgis_setup_notes.txt

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POSTGIS SETUP NOTES

Works with SQLAlchemy and PostgreSQL

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1) install in vagrant
sudo apt-get update (http://technobytz.com/install-postgis-postgresql-9-3-ubuntu.html)
sudo apt-get install postgis (https://www.digitalocean.com/community/tutorials/how-to-install-and-configure-postgis-on-ubuntu-14-04)

2) pip install geoalchemy2

3) setup model.py with postgis column in sqlalchemy
example: latlng = db.Column(Geometry(geometry_type='POINT'), nullable=False)
from sqlalchemy import func
from geoalchemy2 import Geometry

4) createdb

5) psql [database]
CREATE EXTENSION postgis;

6) create/seed your database tables
seeding data must contain formatting like this:
'POINT(%s %s)' % (latitude, longitude)

7) query using:
for approximations of nearby distances using spherical distance, search units nearby by meters; example below searches within 1000m
db.session.query(UnitDetails).filter(func.ST_Distance_Sphere("POINT(37.776164 -122.423355)",UnitDetails.latlng) < 1000).all()


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3219 meters ~ 2 miles