类型错误：INT（）参数必须是字符串或数字，而不是“字典”

Question

I'm try to get all the building structures with the hazard type "High". I have this following query:

>>> reference = FloodHazard.objects.filter(hazard='High')
>>> ids = reference.values('id')
>>> for id in ids:
...     getgeom = FloodHazard.objects.get(id=id).geom
...     getbldg = BuildingStructure.objects.filter(geom__intersects=getgeom).value_list('id')

Traceback (most recent call last):
  File "<console>", line 3, in <module>
  File "C:\Python27\lib\site-packages\django\db\models\manager.py", line 151, in get
    return self.get_queryset().get(*args, **kwargs)
  File "C:\Python27\lib\site-packages\django\db\models\query.py", line 298, in get
    clone = self.filter(*args, **kwargs)
  File "C:\Python27\lib\site-packages\django\db\models\query.py", line 590, in filter
    return self._filter_or_exclude(False, *args, **kwargs)
  File "C:\Python27\lib\site-packages\django\db\models\query.py", line 608, in _filter_or_exclude
    clone.query.add_q(Q(*args, **kwargs))
  File "C:\Python27\lib\site-packages\django\db\models\sql\query.py", line 1198, in add_q
    clause = self._add_q(where_part, used_aliases)
  File "C:\Python27\lib\site-packages\django\db\models\sql\query.py", line 1234, in _add_q
    current_negated=current_negated)
  File "C:\Python27\lib\site-packages\django\db\models\sql\query.py", line 1125, in build_filter
    clause.add(constraint, AND)
  File "C:\Python27\lib\site-packages\django\utils\tree.py", line 104, in add
    data = self._prepare_data(data)
  File "C:\Python27\lib\site-packages\django\contrib\gis\db\models\sql\where.py", line 42, in _prepare_data
    return super(GeoWhereNode, self)._prepare_data(data)
  File "C:\Python27\lib\site-packages\django\db\models\sql\where.py", line 79, in _prepare_data
    value = obj.prepare(lookup_type, value)
  File "C:\Python27\lib\site-packages\django\db\models\sql\where.py", line 352, in prepare
    return self.field.get_prep_lookup(lookup_type, value)
  File "C:\Python27\lib\site-packages\django\db\models\fields\__init__.py", line 369, in get_prep_lookup
    return self.get_prep_value(value)
  File "C:\Python27\lib\site-packages\django\db\models\fields\__init__.py", line 613, in get_prep_value
    return int(value)

TypeError: int() argument must be a string or a number, not 'dict' So, how do I get the IDs of all the FloodHazard with hazard "high"? I understand error but when I try reference.id it returns AttributeError: 'GeoQuerySet' object has no attribute 'id' .

Answer 1

values() returns a list of dicts. You should use the values_list() method instead:

ids = reference.values_list('id', flat=True)

Answer 2

Use:

evntids=EventMember.objects.values('event_id').distinct()

output in dictionary form:

QuerySet [{'event_id': 1}, {'event_id': 2}]

Use:

 evntids=EventMember.objects.values_list('event_id',flat=True).distinct()

output in int form:

QuerySet [1, 2]