python - Django Mysql 复杂注解需要别名

Question

我正在尝试使用变量作为过滤键值。所有变量都采用我想要的精确值，但随后出现此错误。这是我的观点:

@api_view(['POST'])
def map_data(request):
    query_id = request.POST.get('queryId', 1)
    group_name = request.POST.get('group', 'district')
    query = QueryList.objects.using('teldata').get(query_id=query_id)
    groups = query.network_element.lower().split(',')
    values = query.kpi_val.lower().split(',')
    kwargs = {groups[0]: group_name}

    if len(values) == 1:
        if len(groups) == 1:
            report_data = SiteData.objects.using('teldata').values(groups[0]).annotate(
                'latitude', 'longitude', 'latt_call_id', 'long_call_id', Avg(values[0])
            ).filter(**kwargs)
        elif len(groups) == 2:
            report_data = SiteData.objects.using('teldata').values(groups[0], groups[1]).annotate(
                'latitude', 'longitude', 'latt_call_id', 'long_call_id', Avg(values[0])
            ).filter(**kwargs)
    elif len(values) == 2:
        if len(groups) == 1:
            report_data = SiteData.objects.using('teldata').values(groups[0]).annotate(
                'latitude', 'longitude', 'latt_call_id', 'long_call_id', Avg(values[0]), Avg(values[1])
            ).filter(**kwargs)
        elif len(groups) == 2:
            report_data = SiteData.objects.using('teldata').values(groups[0], groups[1]).annotate(
                'latitude', 'longitude', 'latt_call_id', 'long_call_id', Avg(values[0]), Avg(values[1])
            ).filter(**kwargs)
    return Response(report_data)

错误日志如下:

Complex annotations require an alias
Request Method: POST
Request URL:    http://127.0.0.1:5555/data/map-data/
Django Version: 1.9.5
Exception Type: TypeError
Exception Value:    
Complex annotations require an alias
Exception Location: /Library/Python/2.7/site-packages/django/db/models/query.py in annotate, line 895
Python Executable:  /System/Library/Frameworks/Python.framework/Versions/2.7/Resources/Python.app/Contents/MacOS/Python
Python Version: 2.7.10
Python Path:    
['/Users/hco/PycharmProjects/tool/linyit',
 '/Applications/PyCharm CE.app/Contents/helpers/pydev',
 '/Library/Python/2.7/site-packages/pip-8.1.1-py2.7.egg',
 '/Users/hco/PycharmProjects/tool',
 '/Applications/PyCharm CE.app/Contents/helpers/pydev',
 '/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python27.zip',
 '/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7',
 '/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/plat-darwin',
 '/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/plat-mac',
 '/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/plat-mac/lib-scriptpackages',
 '/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python',
 '/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/lib-tk',
 '/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/lib-old',
 '/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/lib-dynload',
 '/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/PyObjC',
 '/Library/Python/2.7/site-packages']

主要是想添加一个可以根据请求参数变化的动态过滤器。如果您建议任何其他方式，我也会打开它。谢谢

Answer 1

这是您的复杂注释。

.annotate(
      'latitude', 'longitude', 'latt_call_id', 'long_call_id'
      ,Avg(values[0]))

此 ORM 查询将转换为包含 group by 子句的 SQL 查询。通常，ORM 将按其中一个键分组并聚合到 values[0] 字段(无论是什么)。但是其他字段 latitude、longitude 等呢？您没有对它们进行任何分组或聚合，这会使查询解析器感到困惑。

如果您花点时间考虑一下这个查询，您会意识到在对特定列进行分组时获取 long_call_id 并没有任何实际意义。 Y事实上老版本的mysql(5.7.6之前)会ch