小编and*_*nik的帖子

我试图将以下查询移植到SQLAlchemy:

SELECT u.username, GROUP_CONCAT(DISTINCT userS.name)
FROM Skills AS filterS 
INNER JOIN UserSkills AS ufs ON filterS.id = ufs.skill_id
INNER JOIN Users AS u ON ufs.user_id = u.id
INNER JOIN UserSkills AS us ON u.id = us.user_id
INNER JOIN Skills AS userS ON us.skill_id = userS.id
WHERE filterS.name IN ('C#', 'SQL')
GROUP BY u.id;

我不明白如何在SQLAlchemy中实现AS语句.这是我目前拥有的:

# User class has attribute skills, that points to class UserSkill
# UserSkill class has attribute skill, that points to class Skill
db.session.query(User.id, User.username, func.group_concat(Skill.name).label('skills')).\
   join(User.skills).\ …

我在单独的文件中定义了一个 Websocket 端点，例如：

from starlette.endpoints import WebSocketEndpoint
from connection_service import ConnectionService


class WSEndpoint(WebSocketEndpoint):
    """Handles Websocket connections"""

    async def on_connect(self,
            websocket: WebSocket,
            connectionService: ConnectionService = Depends(ConnectionService)):
        """Handles new connection"""
        self.connectionService = connectionService
        ...

并在main.py我将端点注册为：

from fastapi import FastAPI
from starlette.routing import WebSocketRoute
from ws_endpoint import WSEndpoint

app = FastAPI(routes=[ WebSocketRoute("/ws", WSEndpoint) ])

但Depends我的终点从未解决。有办法让它发挥作用吗？

另外，FastAPI 中这种机制的目的是什么？我们不能只使用局部/全局变量吗？

我正在使用httpx库，但我认为aiohttp的原理是相同的。如果我在应用程序的整个生命周期中为多个请求创建并重用 AsyncClient，我是否需要在应用程序关闭事件时调用aclose()（或者如果使用 Client）？close或者这些联系会自行消失。

如果我在 Docker 容器中运行应用程序会怎样？这也会是一个因素吗？

我不明白 AsyncClient 或 Client （或 aoihttp 中的 ClientSession）对象下面发生了什么。

感谢帮助。

对于 geojson 类型文件，命名data如下：

{
    "type": "FeatureCollection",
    "name": "entities",
    "features": [{
            "type": "Feature",
            "properties": {
                "Layer": "0",
                "SubClasses": "AcDbEntity:AcDbPolyline",
                "EntityHandle": "1A0"
            },
            "geometry": {
                "type": "LineString",
                "coordinates": [
                    [3220.136443006845184, 3001.530372177397112],
                    [3847.34171007254281, 3000.86074447018018],
                    [3847.34171007254281, 2785.240077064262096],
                    [3260.34191304818205, 2785.240077064262096],
                    [3260.34191304818205, 2795.954148466309107]
                ]
            }
        },
        {
            "type": "Feature",
            "properties": {
                "Layer": "0",
                "SubClasses": "AcDbEntity:AcDbPolyline",
                "EntityHandle": "1A4"
            },
            "geometry": {
                "type": "LineString",
                "coordinates": [
                    [3611.469650131302842, 2846.845982610575902],
                    [3695.231030111376185, 2846.845982610575902],
                    [3695.231030111376185, 2785.240077064262096],
                    [3611.469650131302842, 2785.240077064262096],
                    [3611.469650131302842, 2846.845982610575902]
                ]
            }
        }
    ]
}

我希望实现以下操作data：

1. 将密钥替换EntityHandle …