python-GeoDjango将MultiPolygon解释为LinearRing

我将从Trimble导入一些OSM数据到PostGIS数据库中,以将其作为Django应用程序的一部分进行处理.这对于点和线效果很好,但是我在多边形上挣扎.

导入工作正常：

shp2pgsql -d -I aeroway_polygon_polygon.shp aeroway_polygon | psql

Django InspectDB以一种明智的方式解释数据：

./manage.py inspectdb > models.py

models.py内容：

class AerowayPolygon(models.Model):
    gid = models.AutoField(primary_key=True)
    id = models.FloatField(blank=True, null=True)
    osm_id = models.DecimalField(max_digits=65535, decimal_places=65535, blank=True, null=True)
    z_order = models.FloatField(blank=True, null=True)
    aeroway = models.CharField(max_length=80, blank=True, null=True)
    name = models.CharField(max_length=80, blank=True, null=True)
    name_en = models.CharField(db_column='name:en', max_length=80, blank=True, null=True)  # Field renamed to remove unsuitable characters.
    operator = models.CharField(max_length=80, blank=True, null=True)
    ref = models.CharField(max_length=80, blank=True, null=True)
    faa = models.CharField(max_length=80, blank=True, null=True)
    iata = models.CharField(max_length=80, blank=True, null=True)
    icao = models.CharField(max_length=80, blank=True, null=True)
    website = models.CharField(max_length=80, blank=True, null=True)
    contact_we = models.CharField(db_column='contact:we', max_length=80, blank=True, null=True)  # Field renamed to remove unsuitable characters.
    phone = models.CharField(max_length=80, blank=True, null=True)
    contact_ph = models.CharField(db_column='contact:ph', max_length=80, blank=True, null=True)  # Field renamed to remove unsuitable characters.
    ele = models.CharField(max_length=80, blank=True, null=True)
    tower_type = models.CharField(db_column='tower:type', max_length=80, blank=True, null=True)  # Field renamed to remove unsuitable characters.
    geom = models.MultiPolygonField(srid=0, dim=4, blank=True, null=True)

    class Meta:
        managed = False
        db_table = 'aeroway_polygon'

从数据库访问对象的任何尝试都会导致GEOS抱怨LinearRing.

>>> from data.models import AerowayPolygon
>>> AerowayPolygon.objects.all()[0]
GEOS_ERROR: IllegalArgumentException: Points of LinearRing do not form a closed linestring

错误没有错,这些点不会关闭LineString.但是我感到困惑,因为我认为类型应该是MultiPolygon,因此应该可以正常工作.是什么赋予了？

通过手动尝试从PostGIS中获取几何图形,我进行了更深入的研究.

作为一个众所周知的二进制十六进制字符串,我会得到相同的行为：

>>> from django.contrib.gis.geos import GEOSGeometry
>>> wkb ='01
shp2pgsql -d -I aeroway_polygon_polygon.shp aeroway_polygon | psql

0C00100000001030000C0020000008E0000000064931E4F47DDBF4020B11AB5BC49400000000000000000FFFFFFFFFFFFEFFF006493B23347DDBF442075F9B7BC494 ...     003C9368871FDDBF4020B193B4BC49400000000000000000FFFFFFFFFFFFEFFF'

>>> GEOSGeometry(wkb)

GEOS_ERROR: IllegalArgumentException: Points of LinearRing do not form a closed linestring

解决方法:

MultiPolygon的每个多边形仍应形成闭合的线串.您的数据可能格式错误或已损坏.

您可以尝试使用ST_MakeValid解决此问题.

UPDATE aeroway_polygon
SET geom = ST_Multi(ST_CollectionExtract(ST_Makevalid(geom), 3))
WHERE ST_IsValid(geom) = false;

请注意,我没有测试此查询,但找到了here on gis.stackexchange.

标签：geodjango,postgis,python,django
来源： https://codeday.me/bug/20191109/2012312.html