Question

我正在使用以下内容构建一个包含地理数据的数据库：PostgreSQL 9.1，Django 1.3.1，psycopg2 2.4.5以及使用库GEOS 3.3.0，PostGIS 1.5.4和ProJ 4.7.0。

我有一个命令，可以通过一些优化将形状文件加载到数据库中，使形状更简单。

为了保持模型简单，我将只提出有问题的字段：

class Circonscription(models.Model):
    shape = models.GeometryField()
    simple_shape = models.GeometryField()
    centroid = models.PointField(null=True)

当我想从形状文件创建一个时，我这样做：

Circonscription.objects.create(
            id_cep=feature['id_cep'],
            co_cep=feature['co_cep'],
            nm_cep=feature['nm_cep'],
            nmtri_cep=feature['nmtri_cep'],
            dh_maj=feature['dh_maj'],
            shape=geometry.wkt,
            simple_shape=simple_geometry.wkt,
            centroid=geometry.geos.centroid)

现在，当我运行我的命令时，它会因此错误而失败：

File "/home/pg/Projets/python/myproject/circonscriptions/management/commands/loadshapefiles.py", line 174, in add_boundaries_for_layer
centroid=geometry.geos.centroid)
File "/home/pg/.virtualenvs/myproject/local/lib/python2.7/site-packages/django/db/models/manager.py", line 138, in create
    return self.get_query_set().create(**kwargs)
  File "/home/pg/.virtualenvs/myproject/local/lib/python2.7/site-packages/django/db/models/query.py", line 360, in create
    obj.save(force_insert=True, using=self.db)
  File "/home/pg/.virtualenvs/myproject/local/lib/python2.7/site-packages/django/db/models/base.py", line 460, in save
    self.save_base(using=using, force_insert=force_insert, force_update=force_update)
  File "/home/pg/.virtualenvs/myproject/local/lib/python2.7/site-packages/django/db/models/base.py", line 543, in save_base
    for f in meta.local_fields if not isinstance(f, AutoField)]
  File "/home/pg/.virtualenvs/myproject/local/lib/python2.7/site-packages/django/db/models/fields/subclassing.py", line 28, in inner
    return func(*args, **kwargs)
  File "/home/pg/.virtualenvs/myproject/local/lib/python2.7/site-packages/django/db/models/fields/__init__.py", line 786, in get_db_prep_save
    return connection.ops.value_to_db_decimal(self.to_python(value),
  File "/home/pg/.virtualenvs/myproject/local/lib/python2.7/site-packages/django/db/models/fields/__init__.py", line 761, in to_python
    return decimal.Decimal(value)
  File "/usr/lib/python2.7/decimal.py", line 658, in __new__
    raise TypeError("Cannot convert %r to Decimal" % value)
TypeError: Cannot convert <django.contrib.gis.gdal.field.OFTInteger object at 0x2458b50> to Decimal

有人对此有所了解吗？

Answer 1

它以某种方式与值的编码有关，然后另一个错误是关于this problem，最终解决了它。在将值传递给要保存的模型之前，请务必将值转换为正确的编码（utf-8）。

Answer 2

Decimal需要一个String，但是你正在为它提供一个OTFInteger，你需要在进程的某个地方将它转换为字符串

将OFTInteger转换为Decimal时出现Django错误

2 个答案: