Heroku 和 Postgres 的 Flask SQLAlchemy 错误 (psycopg2.errors.DatatypeMismatch)

【问题标题】：Flask SQLAlchemy Error with Heroku & Postgres (psycopg2.errors.DatatypeMismatch)Heroku 和 Postgres 的 Flask SQLAlchemy 错误 (psycopg2.errors.DatatypeMismatch)
【发布时间】：2020-08-10 18:53:12
【问题描述】：

我已经用 Heroku 安装了我的 Python 应用程序，并且正在从我的 SQLite 数据库转移到 Postgres 数据库。但是，我遇到了 SQLite 不会发生的以下错误：

sqlalchemy.exc.ProgrammingError: (psycopg2.errors.DatatypeMismatch) argument of WHERE must be type boolean, not type character varying
LINE 3: WHERE site_clearance."CreatedOn"
              ^

[SQL: SELECT id 
FROM site_clearance 
WHERE site_clearance."CreatedOn"]
(Background on this error at: http://sqlalche.me/e/f405)

查询的相应 Python 代码用于生成 PDF 文件，正是此查询生成了错误：

# MAKE THE DB QUERIES HERE THAT ARE NEEDED TO BE ENTERED INTO EACH RECORD SHEET
for i in range(0, len(dictionary)):
    query = [r[0] for r in db.session.query(model).filter(model.CreatedOn).values(keys[i])]
    queries.append(query)

正如我所说，SQLite 不会发生此错误，并且问题始于 psycopg2 包。下面的服务器日志中的堆栈跟踪。任何帮助表示赞赏。谢谢！

2020-08-10T17:54:25.630676+00:00 heroku[router]: at=info method=GET path="/makepdf_site_clearance" host=hidden-meadow-44024.herokuapp.com request_id=6bb8550d-afd0-415f-9e8b-bf0a86e63ab4 fwd="88.98.244.118" dyno=web.1 connect=1ms service=37ms status=500 bytes=484 protocol=https
2020-08-10T17:54:25.627181+00:00 app[web.1]: [2020-08-10 17:54:25,620] ERROR in app: Exception on /makepdf_site_clearance [GET]
2020-08-10T17:54:25.627193+00:00 app[web.1]: Traceback (most recent call last):
2020-08-10T17:54:25.627194+00:00 app[web.1]: File "/app/.heroku/python/lib/python3.6/site-packages/sqlalchemy/engine/base.py", line 1284, in _execute_context
2020-08-10T17:54:25.627194+00:00 app[web.1]: cursor, statement, parameters, context
2020-08-10T17:54:25.627195+00:00 app[web.1]: File "/app/.heroku/python/lib/python3.6/site-packages/sqlalchemy/engine/default.py", line 590, in do_execute
2020-08-10T17:54:25.627196+00:00 app[web.1]: cursor.execute(statement, parameters)
2020-08-10T17:54:25.627196+00:00 app[web.1]: psycopg2.errors.DatatypeMismatch: argument of WHERE must be type boolean, not type character varying
2020-08-10T17:54:25.627196+00:00 app[web.1]: LINE 3: WHERE site_clearance."CreatedOn"
2020-08-10T17:54:25.627197+00:00 app[web.1]: ^
2020-08-10T17:54:25.627198+00:00 app[web.1]:
2020-08-10T17:54:25.627198+00:00 app[web.1]:
2020-08-10T17:54:25.627199+00:00 app[web.1]: The above exception was the direct cause of the following exception:
2020-08-10T17:54:25.627199+00:00 app[web.1]:
2020-08-10T17:54:25.627200+00:00 app[web.1]: Traceback (most recent call last):
2020-08-10T17:54:25.627200+00:00 app[web.1]: File "/app/.heroku/python/lib/python3.6/site-packages/flask/app.py", line 2447, in wsgi_app
2020-08-10T17:54:25.627201+00:00 app[web.1]: response = self.full_dispatch_request()
2020-08-10T17:54:25.627201+00:00 app[web.1]: File "/app/.heroku/python/lib/python3.6/site-packages/flask/app.py", line 1952, in full_dispatch_request
2020-08-10T17:54:25.627202+00:00 app[web.1]: rv = self.handle_user_exception(e)
2020-08-10T17:54:25.627202+00:00 app[web.1]: File "/app/.heroku/python/lib/python3.6/site-packages/flask/app.py", line 1821, in handle_user_exception
2020-08-10T17:54:25.627203+00:00 app[web.1]: reraise(exc_type, exc_value, tb)
2020-08-10T17:54:25.627203+00:00 app[web.1]: File "/app/.heroku/python/lib/python3.6/site-packages/flask/_compat.py", line 39, in reraise
2020-08-10T17:54:25.627203+00:00 app[web.1]: raise value
2020-08-10T17:54:25.627204+00:00 app[web.1]: File "/app/.heroku/python/lib/python3.6/site-packages/flask/app.py", line 1950, in full_dispatch_request
2020-08-10T17:54:25.627204+00:00 app[web.1]: rv = self.dispatch_request()
2020-08-10T17:54:25.627205+00:00 app[web.1]: File "/app/.heroku/python/lib/python3.6/site-packages/flask/app.py", line 1936, in dispatch_request
2020-08-10T17:54:25.627205+00:00 app[web.1]: return self.view_functions[rule.endpoint](**req.view_args)
2020-08-10T17:54:25.627206+00:00 app[web.1]: File "/app/.heroku/python/lib/python3.6/site-packages/flask_login/utils.py", line 272, in decorated_view
2020-08-10T17:54:25.627206+00:00 app[web.1]: return func(*args, **kwargs)
2020-08-10T17:54:25.627207+00:00 app[web.1]: File "/app/constructaerp02/routes.py", line 1191, in makepdf_site_clearance
2020-08-10T17:54:25.627207+00:00 app[web.1]: p = pdf_make(model=SiteClearance, dictionary=SiteClearance_dictionary, title='Site Clearance')
2020-08-10T17:54:25.627208+00:00 app[web.1]: File "/app/constructaerp02/pdf_creator.py", line 23, in pdf_make
2020-08-10T17:54:25.627208+00:00 app[web.1]: query = [r[0] for r in db.session.query(model).filter(model.CreatedOn).values(keys[i])]
2020-08-10T17:54:25.627209+00:00 app[web.1]: File "/app/.heroku/python/lib/python3.6/site-packages/sqlalchemy/orm/query.py", line 1530, in values
2020-08-10T17:54:25.627209+00:00 app[web.1]: return iter(q)
2020-08-10T17:54:25.627210+00:00 app[web.1]: File "/app/.heroku/python/lib/python3.6/site-packages/sqlalchemy/orm/query.py", line 3481, in __iter__
2020-08-10T17:54:25.627210+00:00 app[web.1]: return self._execute_and_instances(context)
2020-08-10T17:54:25.627211+00:00 app[web.1]: File "/app/.heroku/python/lib/python3.6/site-packages/sqlalchemy/orm/query.py", line 3506, in _execute_and_instances
2020-08-10T17:54:25.627211+00:00 app[web.1]: result = conn.execute(querycontext.statement, self._params)
2020-08-10T17:54:25.627212+00:00 app[web.1]: File "/app/.heroku/python/lib/python3.6/site-packages/sqlalchemy/engine/base.py", line 1020, in execute
2020-08-10T17:54:25.627212+00:00 app[web.1]: return meth(self, multiparams, params)
2020-08-10T17:54:25.627212+00:00 app[web.1]: File "/app/.heroku/python/lib/python3.6/site-packages/sqlalchemy/sql/elements.py", line 298, in _execute_on_connection
2020-08-10T17:54:25.627213+00:00 app[web.1]: return connection._execute_clauseelement(self, multiparams, params)
2020-08-10T17:54:25.627213+00:00 app[web.1]: File "/app/.heroku/python/lib/python3.6/site-packages/sqlalchemy/engine/base.py", line 1139, in _execute_clauseelement
2020-08-10T17:54:25.627214+00:00 app[web.1]: distilled_params,
2020-08-10T17:54:25.627215+00:00 app[web.1]: File "/app/.heroku/python/lib/python3.6/site-packages/sqlalchemy/engine/base.py", line 1324, in _execute_context
2020-08-10T17:54:25.627215+00:00 app[web.1]: e, statement, parameters, cursor, context
2020-08-10T17:54:25.627216+00:00 app[web.1]: File "/app/.heroku/python/lib/python3.6/site-packages/sqlalchemy/engine/base.py", line 1518, in _handle_dbapi_exception
2020-08-10T17:54:25.627216+00:00 app[web.1]: sqlalchemy_exception, with_traceback=exc_info[2], from_=e
2020-08-10T17:54:25.627216+00:00 app[web.1]: File "/app/.heroku/python/lib/python3.6/site-packages/sqlalchemy/util/compat.py", line 178, in raise_
2020-08-10T17:54:25.627217+00:00 app[web.1]: raise exception
2020-08-10T17:54:25.627217+00:00 app[web.1]: File "/app/.heroku/python/lib/python3.6/site-packages/sqlalchemy/engine/base.py", line 1284, in _execute_context
2020-08-10T17:54:25.627218+00:00 app[web.1]: cursor, statement, parameters, context
2020-08-10T17:54:25.627218+00:00 app[web.1]: File "/app/.heroku/python/lib/python3.6/site-packages/sqlalchemy/engine/default.py", line 590, in do_execute
2020-08-10T17:54:25.627219+00:00 app[web.1]: cursor.execute(statement, parameters)
2020-08-10T17:54:25.627223+00:00 app[web.1]: sqlalchemy.exc.ProgrammingError: (psycopg2.errors.DatatypeMismatch) argument of WHERE must be type boolean, not type character varying
2020-08-10T17:54:25.627224+00:00 app[web.1]: LINE 3: WHERE site_clearance."CreatedOn"
2020-08-10T17:54:25.627224+00:00 app[web.1]: ^
2020-08-10T17:54:25.627224+00:00 app[web.1]:
2020-08-10T17:54:25.627225+00:00 app[web.1]: [SQL: SELECT id
2020-08-10T17:54:25.627225+00:00 app[web.1]: FROM site_clearance
2020-08-10T17:54:25.627226+00:00 app[web.1]: WHERE site_clearance."CreatedOn"]
2020-08-10T17:54:25.627233+00:00 app[web.1]: (Background on this error at: http://sqlalche.me/e/f405)
2020-08-10T17:54:25.631141+00:00 app[web.1]: 10.63.174.10 - - [10/Aug/2020:17:54:25 +0000] "GET

【问题讨论】：

  • 请在以后清理您的日志，这将有助于人们识别您的问题是可以回答的。这意味着删除时间戳，因为它们很难阅读

标签： python postgresql sqlalchemy flask-sqlalchemy heroku-postgres


【解决方案1】：

错误准确地说明了它发生了什么；你用的是.filter(model.createdOn)，但是createdOn是什么？

一个选项是 .filter(model.createdOn > datetime.now() - timedelta(days=7)) 会起作用，因为它会生成 SQL "createdOn" > "2020-08-03 12:00:00" 或类似的东西。

另一个选项是.filter(model.createdOn.isnot(None)) 或.filter(~model.createdOn.is_(None))，它们都生成"createdOn" IS NOT NULL。

在这种情况下，打印查询通常是个好主意，为变量输入一些虚拟值，如果直接执行 SQL，看看它是否运行。这对调试有很大帮助！

【讨论】：

  • 谢谢。那解决了它。之后我也遇到了其他问题，这些问题没有出现在 SQLite 中，但出现在 Postgres 中。我用 python 控制台缩小了范围，直接在那里输入查询，直到找到 bogey 参数。
猜你喜欢
  • 2021-07-22
  • 2018-07-30
  • 1970-01-01
  • 2014-05-09
  • 2013-07-12
  • 1970-01-01
  • 2021-06-04
  • 2017-12-26
  • 1970-01-01
相关资源
最近更新 更多
热门标签
Java Python linux javascript Mysql C# Docker 算法 前端 SpringBoot Redis Vue spring 设计模式 .net core .net kubernetes c++ 数据库 数据结构 大数据 js 机器学习 微服务 Android Go 程序员 面试 JVM ASP.net core 云原生 人工智能 后端 PHP git CSS golang k8s Nginx Django mybatis 深度学习 多线程 React 架构 devops 爬虫 云计算 Spring Boot LeetCode