Point type in sqlalchemy?

问题

I found this regarding Point type in Postgres: http://www.postgresql.org/docs/current/interactive/datatype-geometric.html

Is there the SQLAlchemy version of this?

I am storing values in this manner: (40.721959482, -73.878993913)

回答1:

You can use geoalchemy2 whis is an extension to sqlalchemy and can be used with flask-sqlalchemy too.

from sqlalchemy import Column
from geoalchemy2 import Geometry
# and import others

class Shop(db.Model):
    # other fields
    coordinates = Column(Geometry('POINT'))

回答2:

I found out it's a slight modification of Mohammad's answer.

Yes I need to add a point column via geo/sqlalchemy

from sqlalchemy import Column
from geoalchemy2 import Geometry
# and import others

class Shop(db.Model):
    # other fields
    coordinates = Column(Geometry('POINT'))

On my PostGIS/Gres and PGloader side, since I'm loading from a csv that formats my latitude and longitude points as: "(40.721959482, -73.878993913)" I needed to do a macro in vim for all of my entries (there's a lot) in order to force that column to adhere to how points are created in PostGIS, so I turned the csv column into point(40.721959482 -73.878993913), then upon table creation set the location column with the datatype as geometry(point) location geometry(point).

回答3:

You can extend UserDefinedType to achieve what you want.

Here's an example I found that gets pretty close to what you want subclassing UserDefinedType

Note that Mohammad Amin's answer is valid only if your point is intended to be a geographic point (latitude and longitude constraints). It doesn't apply if you want to represent any point on a plane. Also, in that case you would need to install the PostGIS extension, which I encourage if you are working with geography points as it provides a lot of utlities and extra functions.

来源：https://stackoverflow.com/questions/37233116/point-type-in-sqlalchemy

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postgresql

Flask

sqlalchemy

flask-sqlalchemy