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我有两个模型，我想将它们关联起来（多对多），但我不想为此使用辅助表，因为位置（geom 属性）会不断变化。我正在使用 ST_Intersects，这是来自 postgis 的函数并返回一个布尔值，当几何与其他几何相交时为真。

from flask_sqlalchemy import SQLAlchemy
from sqlalchemy.sql.functions import func
from flask import Flask
from geoalchemy2.types import Geometry

db = SQLAlchemy()

def create_app():
    app = Flask(...)
    ...
    db.init_app(app)
    ...
    return app


class City(db.Model):
    __tablename__ = "city"
    id = db.Column(db.Integer, primary_key=True)
    geom = db.Column(Geometry("POLYGON",4326))
    ...

class Location(db.Model):
    __tablename__ = "location"
    id = db.Column(db.Integer, primary_key=True)
    geom = db.Column(Geometry("POLYGON",4326))
    ...
    cities = db.relationship(City, primaryjoin=func.ST_Instesects(geom,City.geom), remote_side=id, foreign_keys=City.id, viewonly=True, uselist=True, lazy='joined')

使用此配置抛出异常

sqlalchemy.exc.ArgumentError: Relationship Location.cities could not determine any unambiguous local/remote column pairs based on join condition and remote_side arguments.  Consider using the remote() annotation to accurately mark those elements of the join condition that are on the remote side of the relationship.

但是如果我在primaryjoin中添加remote()和foreign()，sqlalchemy会抛出同样的异常

使用纯 SQL，我可以：

SELECT city.* FROM location loc JOIN city ON ST_Intersects(city.geom,loc.geom)
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