Docker：错误：字符 13 处不存在关系“用户”答案

【问题标题】：Docker: ERROR: relation "users" does not exist at character 13Docker：错误：字符 13 处不存在关系“用户”
【发布时间】：2021-12-09 23:49:52
【问题描述】：

我正在尝试对使用 Python 和 FastAPI 制作的应用程序进行 dockerize。我成功创建了图像和容器。

我尝试对我的 postgres 数据库进行 dockerize，它已成功完成，直到我尝试创建新用户。它抛出以下错误：

 ERROR:  relation "users" does not exist at character 13
10 02:24:37.586 UTC [71] STATEMENT:  INSERT INTO users (email, password) VALUES ('sumitdadwal11@gmail.com', '$2b$12$VNya4IkKSGCuapswkJrh3u6POJVsdU2GSeIaV/ya4GprxNqEt5oim') RETURNING users.id

它在我的 FastAPI 应用图像中显示以下错误：

 Traceback (most recent call last):

  File "/usr/local/lib/python3.9/site-packages/sqlalchemy/engine/base.py", line 1802, in _execute_context

    self.dialect.do_execute(

  File "/usr/local/lib/python3.9/site-packages/sqlalchemy/engine/default.py", line 719, in do_execute

    cursor.execute(statement, parameters)

psycopg2.errors.UndefinedTable: relation "users" does not exist

LINE 1: INSERT INTO users (email, password) VALUES ('sumitdadwal11@g...

                    ^

    The above exception was the direct cause of the following exception:


Traceback (most recent call last):

  File "/usr/local/lib/python3.9/site-packages/uvicorn/protocols/http/httptools_impl.py", line 376, in run_asgi

    result = await app(self.scope, self.receive, self.send)

  File "/usr/local/lib/python3.9/site-packages/uvicorn/middleware/proxy_headers.py", line 75, in __call__

    return await self.app(scope, receive, send)

  File "/usr/local/lib/python3.9/site-packages/fastapi/applications.py", line 208, in __call__

    await super().__call__(scope, receive, send)

  File "/usr/local/lib/python3.9/site-packages/starlette/applications.py", line 112, in __call__

    await self.middleware_stack(scope, receive, send)

  File "/usr/local/lib/python3.9/site-packages/starlette/middleware/errors.py", line 181, in __call__

    raise exc

  File "/usr/local/lib/python3.9/site-packages/starlette/middleware/errors.py", line 159, in __call__

    await self.app(scope, receive, _send)

  File "/usr/local/lib/python3.9/site-packages/starlette/middleware/cors.py", line 84, in __call__

    await self.app(scope, receive, send)

  File "/usr/local/lib/python3.9/site-packages/starlette/exceptions.py", line 82, in __call__

    raise exc

  File "/usr/local/lib/python3.9/site-packages/starlette/exceptions.py", line 71, in __call__

    await self.app(scope, receive, sender)

  File "/usr/local/lib/python3.9/site-packages/starlette/routing.py", line 656, in __call__

    await route.handle(scope, receive, send)

  File "/usr/local/lib/python3.9/site-packages/starlette/routing.py", line 259, in handle

    await self.app(scope, receive, send)

  File "/usr/local/lib/python3.9/site-packages/starlette/routing.py", line 61, in app

    response = await func(request)

  File "/usr/local/lib/python3.9/site-packages/fastapi/routing.py", line 226, in app

    raw_response = await run_endpoint_function(

  File "/usr/local/lib/python3.9/site-packages/fastapi/routing.py", line 161, in run_endpoint_function

    return await run_in_threadpool(dependant.call, **values)

  File "/usr/local/lib/python3.9/site-packages/starlette/concurrency.py", line 39, in run_in_threadpool

    return await anyio.to_thread.run_sync(func, *args)

  File "/usr/local/lib/python3.9/site-packages/anyio/to_thread.py", line 28, in run_sync

    return await get_asynclib().run_sync_in_worker_thread(func, *args, cancellable=cancellable,

  File "/usr/local/lib/python3.9/site-packages/anyio/_backends/_asyncio.py", line 818, in run_sync_in_worker_thread

    return await future

  File "/usr/local/lib/python3.9/site-packages/anyio/_backends/_asyncio.py", line 754, in run

    result = context.run(func, *args)

  File "/usr/src/app/./app/routers/user.py", line 18, in create_user

    db.commit()

  File "/usr/local/lib/python3.9/site-packages/sqlalchemy/orm/session.py", line 1428, in commit

    self._transaction.commit(_to_root=self.future)

  File "/usr/local/lib/python3.9/site-packages/sqlalchemy/orm/session.py", line 829, in commit

    self._prepare_impl()

  File "/usr/local/lib/python3.9/site-packages/sqlalchemy/orm/session.py", line 808, in _prepare_impl

    self.session.flush()

  File "/usr/local/lib/python3.9/site-packages/sqlalchemy/orm/session.py", line 3345, in flush

    self._flush(objects)

  File "/usr/local/lib/python3.9/site-packages/sqlalchemy/orm/session.py", line 3485, in _flush

    transaction.rollback(_capture_exception=True)

  File "/usr/local/lib/python3.9/site-packages/sqlalchemy/util/langhelpers.py", line 70, in __exit__

    compat.raise_(

  File "/usr/local/lib/python3.9/site-packages/sqlalchemy/util/compat.py", line 207, in raise_

    raise exception

  File "/usr/local/lib/python3.9/site-packages/sqlalchemy/orm/session.py", line 3445, in _flush

    flush_context.execute()

  File "/usr/local/lib/python3.9/site-packages/sqlalchemy/orm/unitofwork.py", line 456, in execute

    rec.execute(self)

  File "/usr/local/lib/python3.9/site-packages/sqlalchemy/orm/unitofwork.py", line 630, in execute

    util.preloaded.orm_persistence.save_obj(

  File "/usr/local/lib/python3.9/site-packages/sqlalchemy/orm/persistence.py", line 244, in save_obj

    _emit_insert_statements(

  File "/usr/local/lib/python3.9/site-packages/sqlalchemy/orm/persistence.py", line 1221, in _emit_insert_statements

    result = connection._execute_20(

  File "/usr/local/lib/python3.9/site-packages/sqlalchemy/engine/base.py", line 1614, in _execute_20

    return meth(self, args_10style, kwargs_10style, execution_options)

  File "/usr/local/lib/python3.9/site-packages/sqlalchemy/sql/elements.py", line 325, in _execute_on_connection

    return connection._execute_clauseelement(

  File "/usr/local/lib/python3.9/site-packages/sqlalchemy/engine/base.py", line 1481, in _execute_clauseelement

    ret = self._execute_context(

  File "/usr/local/lib/python3.9/site-packages/sqlalchemy/engine/base.py", line 1845, in _execute_context

    self._handle_dbapi_exception(

  File "/usr/local/lib/python3.9/site-packages/sqlalchemy/engine/base.py", line 2026, in _handle_dbapi_exception

    util.raise_(

  File "/usr/local/lib/python3.9/site-packages/sqlalchemy/util/compat.py", line 207, in raise_

    raise exception

  File "/usr/local/lib/python3.9/site-packages/sqlalchemy/engine/base.py", line 1802, in _execute_context

    self.dialect.do_execute(

  File "/usr/local/lib/python3.9/site-packages/sqlalchemy/engine/default.py", line 719, in do_execute

    cursor.execute(statement, parameters)

sqlalchemy.exc.ProgrammingError: (psycopg2.errors.UndefinedTable) relation "users" does not exist

LINE 1: INSERT INTO users (email, password) VALUES ('sumitdadwal11@g...

                    ^


[SQL: INSERT INTO users (email, password) VALUES (%(email)s, %(password)s) RETURNING users.id]

[parameters: {'email': 'sumitdadwal11@gmail.com', 'password': '$2b$12$5tcxP4b0hwVJpmHfyF10wuosYsdIxBkm1nhk1b1BZlLFZyCymodhK'}]

(Background on this error at: https://sqlalche.me/e/14/f405)

这是我的 docker-compose.yml 文件：

   version: "3"
services: 
  api:
    build: .
    ports:
      - 8000:8000
    # env_file:
    #      ./.env
    environment:
      - DATABASE_HOSTNAME=postgres
      - DATABASE_PORT=5432
      - DATABASE_PASSWORD=password123
      - DATABASE_NAME=fastapi
      - DATABASE_USERNAME=postgres
      - SECRET_KEY=secretkeysecretkeysecretkeysecretkey
      - ALGORITHM=HS256
      - ACCESS_TOKEN_EXPIRE_MINUTES=30
  postgres:
    image: postgres
    environment:
      - POSTGRES_PASSWORD=password123
      - POSTGRES_DB=fastapi
    
    volumes:
      - postgres-db:/var/lib/postgresql/data

volumes:
  postgres-db:

这是我的 Dockerfile：

  FROM python:3.9.9

WORKDIR /usr/src/app

COPY requirements.txt ./

RUN pip install --no-cache-dir -r requirements.txt

COPY . .

CMD ["uvicorn", "app.main:app", "--host", "0.0.0.0", "--port", "8000"]

首先我认为我的代码有问题，但是当我在我的系统上本地运行它时它工作正常。

另外，我对 docker 很陌生。

我尝试了不同的在线解决方案，但没有成功。

我认为它连接到名为 postgres 的错误表，但我找不到它背后的原因。

更新：我注意到的是我的 postgress 服务器有三个数据库： -fastapi -fastapi-project

postgres fastapi 是我想连接的那个，但我认为它正在连接到 postgres，我不记得创建那个数据库。 postgres 数据库也没有表，因此它找不到用户表是有道理的。但问题是如何更改数据库？

如果您需要任何其他信息，请告诉我。

提前致谢！

【问题讨论】：

您确定您已连接到数据库fastapi？要么你在错误的数据库中，例如在维护数据库postgres，或者你忘记创建表user
我认为我在错误的数据库中，即 postgres 并且它根本没有表。我该如何改变它。我正在关注一个教程，并且我已经完成了与显示的完全一样的所有事情。如果需要更多信息，请告诉我。
如果您使用的是psql，只需输入\c fastapi 并回车即可：)
对不起，我不明白我在哪里输入 \c fastapi 这是一个命令，因为我在 Windows 机器上。对不起，如果这是基本的东西，我对 docker 是全新的。

标签： python postgresql docker fastapi

【解决方案1】：

按照 Sanjeev 的教程，我遇到了同样的问题。鉴于您的设置，您正在连接到正确的数据库，问题是它没有表。这可以通过 Alembic 解决。
在您的docker-compose.yml 中，在api: 下添加以下行：

command: bash -c "alembic upgrade head && uvicorn app.main:app --host 0.0.0.0 --port 8000 --reload"

就是这样！

要检查表是否已成功创建，请在项目文件夹中打开一个终端并执行以下操作：

运行 docker compose
```
docker-compose up -d
```
找到 pg 容器名称，在你的情况下它应该类似于 fastapi-postgres-1，然后在你的 pg 容器中启动一个 bash 会话
```
docker ps
docker exec -it fastapi-postgres-1 bash
```
从这里访问psql 并找到您的数据库名称，在您的情况下应该是fastapi
```
su - postgres
psql
\l
```
访问您的数据库并检查表是否已创建
```
\c fastapi
\dt
```

如果结果是这样的，你就可以走了。

              List of relations
 Schema |      Name       | Type  |  Owner   
--------+-----------------+-------+----------
 public | alembic_version | table | postgres
 public | posts           | table | postgres
 public | users           | table | postgres
 public | votes           | table | postgres
(4 rows)

【讨论】：