Use key_name instead of link_id
Some entities do not have a link_id, but all entities are guaranteed
to have a key_name (or an id).
INSERT INTO geoapp_city ("name", "point") VALUES ('Houston', 'SRID=4326;POINT (-95.363151 29.763374)');
INSERT INTO geoapp_city ("name", "point") VALUES ('Dallas', 'SRID=4326;POINT (-96.801611 32.782057)');
INSERT INTO geoapp_city ("name", "point") VALUES ('Oklahoma City', 'SRID=4326;POINT (-97.521157 34.464642)');
INSERT INTO geoapp_city ("name", "point") VALUES ('Wellington', 'SRID=4326;POINT (174.783117 -41.315268)');
INSERT INTO geoapp_city ("name", "point") VALUES ('Pueblo', 'SRID=4326;POINT (-104.609252 38.255001)');
INSERT INTO geoapp_city ("name", "point") VALUES ('Lawrence', 'SRID=4326;POINT (-95.235060 38.971823)');
INSERT INTO geoapp_city ("name", "point") VALUES ('Chicago', 'SRID=4326;POINT (-87.650175 41.850385)');
INSERT INTO geoapp_city ("name", "point") VALUES ('Victoria', 'SRID=4326;POINT (-123.305196 48.462611)');