Question

我刚刚开始实践Python-django

我正在使用django视图中的查询尝试从DB中过滤对象。从网址传来三个参数，我想做一个＆＃39;或者＆＃39;对参数的条件。很少有参数可以为空。

 if 'custName' in request.GET :
        custName = request.GET['custName']
        if custName is not None and custName != '':
            files_name=LopFtsMLoanFilesMaster.objects.filter(customer_name__contains=custName)

 if 'custId' in request.GET and request.GET['custId']:
            custId = request.GET['custId']
            if custId is not None and custId != '':
                files_id=LopFtsMLoanFilesMaster.objects.filter(customer_id__containis=custId)

 if 'address' in request.GET and request.GET['address']:
            address= request.GET['address']
            if address is not None and address != '':
                files_address =LopFtsMLoanFilesMaster.objects.filter(original_address1__contains=address)

 files = files_name | files_id | files_address

 return render(request, 'file_enquiry.html',
                     {'results': files})

但我收到local variable 'files_id' referenced before assignment错误。

Answer 1

如果'custId' in request.GET and request.GET['custId']为false，则files_id永远不会被定义，但您想无条件地引用它。因此，您必须在条件之前定义默认值（例如set()），以确保始终定义它。

您的代码可以大大简化：

def filtered(request_param, model_field):
    param_val = request.GET.get(request_param)  # returns None if request_param is not in request.GET
    if not param_val:  # if param_val in (None, '')
        return set()
    return LopFtsMLoanFilesMaster.objects.filter(**{model_field + '__contains': param_val})

files = (filtered('custName', 'customer_name') |
         filtered('custId', 'customer_id') |
         filtered('address', 'original_address'))

Python - django：读取多个请求参数以进行查询

1 个答案: