Django中利用type动态操作数据库表

create_model(name, fields=None, app_label=‘‘, module=‘‘, options=None, admin=None): class Meta: pass if app_label: setattr(Meta, ‘app_label‘, app_label) if options is not None: for key, value in options.items(): setattr(Meta, key, value) attrs = {‘__module__‘: module, ‘Meta‘: Meta} if fields: attrs.update(fields) # 继承models.Model return type(name, (models.Model,), attrs)

 

2. 调用create_model, 返回的custom_model就是表对应的ORM模型

def new_stock(tab_name):
    """
    动态创建数据模型
    :param tab_name: 表名
    :return: 返回模型类
    """
    fields = {
        ‘ts_code‘: models.CharField(max_length=20),
        ‘trade_date‘: models.CharField(max_length=20, unique=True),
        ‘open‘: models.FloatField(null=False, default=0.0),
        ‘high‘: models.FloatField(null=False, default=0.0),
        ‘low‘: models.FloatField(null=False, default=0.0),
        ‘close‘: models.FloatField(null=False, default=0.0),
        ‘pre_close‘: models.FloatField(null=False, default=0.0),
        ‘change‘: models.FloatField(null=False, default=0.0),
        ‘pct_chg‘: models.FloatField(null=False, default=0.0),
        ‘vol‘: models.FloatField(null=False, default=0.0),
        ‘amount‘: models.FloatField(null=False, default=0.0)
    }
    options = {‘ordering‘: [‘trade_date‘], ‘db_table‘: tab_name, }
    custom_model = create_model(tab_name, fields, options=options, app_label=‘stock‘, module=‘stock.models‘)
    return custom_model

 

3. http请求按日期降序排列的股票日线数据。

def stock_detail(request, pk):
    tab_name = ‘stock_‘ + pk
    stock_mod = new_stock(tab_name)

    # 查询
    if request.method == ‘GET‘:
        limit = request.GET.get(‘limit‘)
        offset = request.GET.get(‘offset‘)
        # 查询总记录条数
        total = stock_mod.objects.count()

        # 结果按日期降序排列
        datalist = stock_mod.objects.all().order_by(‘-trade_date‘)[int(offset): int(offset)+int(limit)]
        json_list = []

        import json
        # 返回json字符串
        for data in datalist:
            json_dict = model_to_dict(data)
            json_list.append(json_dict)

        result = dict()
        rows = list()
        result[‘total‘] = total
        result[‘rows‘] = json_list

        logger.info(‘获取股票列表‘)
        return JsonResponse(result, safe=False)

HTTP请求：GET /stock/000002/?offset=0&limit=10

000002与"stock_"组合成表名"stock_000002"

offset为数据的起始位置

limit为返回数据的条数

按表查询得到的datalist数据组织成json格式返回浏览器。

 

Django中利用type动态操作数据库表

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