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

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数据库迁移到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)

该查询的相应Python代码用于生成PDF文件，而该查询正在生成错误：

# 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，而麻烦是从psycopg2软件包开始的。来自以下服务器日志的堆栈跟踪。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,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,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",in _execute_context
2020-08-10T17:54:25.627218+00:00 app[web.1]: cursor,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",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 

解决方法

错误确切说明了正在发生的事情；您正在使用QGraphicsBlurEffect *effect = new QGraphicsBlurEffect(this); effect->setBlurRadius(100); QRadialGradient grad(QPoint(50,50),50); grad.setSpread(QGradient::RepeatSpread); grad.setColorAt(0,QColor(0,0)); grad.setColorAt(1,QColor(100,100,100)); QGraphicsRectItem *item = new QGraphicsRectItem(0,100); item->setBrush(QBrush(grad)); item->setGraphicsEffect(effect); ，但是.filter(model.createdOn)是什么？

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

另一种选择是"createdOn" > "2020-08-03 12:00:00"或.filter(model.createdOn.isnot(None))，两者都会生成.filter(~model.createdOn.is_(None))。

在这种情况下，通常最好打印查询，为变量输入一些虚拟值，然后查看是否在直接执行SQL的情况下运行。这对调试很有帮助！