POST上的Sqlalchemy检查记录是否已存在并将其发送回

如何解决POST上的Sqlalchemy检查记录是否已存在并将其发送回

我有几个端点都遇到相同类型的问题。检查记录是否已经存在。在这种特定情况下，我正在验证是否已将具有相同url值的记录添加到数据库中。

端点

api.add_resource(EventEntries,'/events/<int:event_id>/entries')

加载程序

class Entry (Resource):
    #RETURNS A SINGLE EVENT
    def get(self,entry_id):
        schema = EntrySchema()
        result = db.session.query(EntryModel).filter(EntryModel.id == entry_id)
        return schema.dump(result,many=True),200

    #PUTS A SINGLE EVENT
    def put(self,entry_id):
        event_id = event_id
        title = request.json['title']
        description = request.json['description']
        type = request.json['type']
        domain = request.json['domain']
        language = request.json['language']
        publishdate = request.json['publishdate']
        url = request.json['url']

        entry = EntryModel(event_id=event_id,title=title,description=description,type=type,domain=domain,language=language,publishdate=publishdate,url=url)

        db.session.add(event)
        db.session.commit()

        data = ({'id' :entry.id,'title': entry.title,'description': entry.description,'type': entry.type,'domain': entry.domain,'language': entry.language,'publishdate': entry.publishdate,'url': entry.url})

        response = jsonify(data)
        response.status_code = 200 # or 400 or whatever
        return response

修改

我修改了上面的文件以包括以下几行，这些行检查记录是否存在并尝试返回记录。即使条目不存在，这也会导致返回一个空数组。

    # If record already exists
    schema = EntrySchema()
    result = db.session.query(EntryModel).filter(EntryModel.url == request.json['url'])
    print(result)
    print(request.json['url'])

    if  result is not None:
        print("Record Already exists")
        return schema.dump(result,200

    else:

解决方法

已解决：

我添加了它，而不是上面的建议。

    # If record already exists
    schema = EntrySchema()
    result = db.session.query(EntryModel).filter(EntryModel.url == request.json['url']).first()
    print(result)

    if not result is None:
        print("Record Already exists")
        return schema.dump(result,many=False),200