【发布时间】：2021-01-10 15:00:38
【问题描述】：
我正在开发一个使用flask-restx 的flask 应用程序，以使用sqlalchemy 将嵌套的list 保存到托管在RDS 上的PostgreSQL 数据库中。每个嵌套的list 将是表中的一行。假设如下嵌套list
csv_json_response = [
[
1577837700,
63.2
],
[
1577838600,
61.0
],
[
1577839500,
58.9
],
[
1577840400,
57.0
],
[
1577841300,
55.3
]
]
我正在尝试将其插入数据库，如下所示：
import sqlalchemy as db
if (type(csv_json_response) is list and len(csv_json_response) > 0):
db.session.bulk_insert_mappings(Upload, csv_json_response)
elif (type(csv_json_response) is dict):
item = Upload(**csv_json_response)
print(item)
db.session.add(item)
print('Data ready')
db.session.commit()
print('Data dumped into the dummy DB')
Upload 在哪里
class Upload(db.Model):
__tablename__ = "user_uploaded_CSV"
id = db.Column(db.Integer, primary_key=True)
timestamp = db.Column(db.Integer, nullable=False)
value = db.Column(db.Float(precision=2), nullable=False)
当我尝试运行它时，它会抛出以下错误：
Error on request:
Traceback (most recent call last):
File "/home/cortex/.local/share/virtualenvs/upload-service-3zz-Lxl9/lib/python3.7/site-packages/sqlalchemy/engine/base.py", line 1257, in _execute_context
cursor, statement, parameters, context
File "/home/cortex/.local/share/virtualenvs/upload-service-3zz-Lxl9/lib/python3.7/site-packages/sqlalchemy/dialects/postgresql/psycopg2.py", line 873, in do_executemany
cursor.executemany(statement, parameters)
psycopg2.errors.NotNullViolation: null value in column "timestamp" violates not-null constraint
DETAIL: Failing row contains (6, null, null).
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "/home/cortex/.local/share/virtualenvs/upload-service-3zz-Lxl9/lib/python3.7/site-packages/werkzeug/serving.py", line 323, in run_wsgi
execute(self.server.app)
File "/home/cortex/.local/share/virtualenvs/upload-service-3zz-Lxl9/lib/python3.7/site-packages/werkzeug/serving.py", line 312, in execute
application_iter = app(environ, start_response)
File "/home/cortex/.local/share/virtualenvs/upload-service-3zz-Lxl9/lib/python3.7/site-packages/flask/app.py", line 2464, in __call__
return self.wsgi_app(environ, start_response)
File "/home/cortex/.local/share/virtualenvs/upload-service-3zz-Lxl9/lib/python3.7/site-packages/flask/app.py", line 2450, in wsgi_app
response = self.handle_exception(e)
File "/home/cortex/.local/share/virtualenvs/upload-service-3zz-Lxl9/lib/python3.7/site-packages/flask_restx/api.py", line 638, in error_router
return original_handler(f)
File "/home/cortex/.local/share/virtualenvs/upload-service-3zz-Lxl9/lib/python3.7/site-packages/flask/app.py", line 1867, in handle_exception
reraise(exc_type, exc_value, tb)
File "/home/cortex/.local/share/virtualenvs/upload-service-3zz-Lxl9/lib/python3.7/site-packages/flask/_compat.py", line 39, in reraise
raise value
File "/home/cortex/.local/share/virtualenvs/upload-service-3zz-Lxl9/lib/python3.7/site-packages/flask_restx/api.py", line 636, in error_router
return self.handle_error(e)
File "/home/cortex/.local/share/virtualenvs/upload-service-3zz-Lxl9/lib/python3.7/site-packages/flask/app.py", line 2447, in wsgi_app
response = self.full_dispatch_request()
File "/home/cortex/.local/share/virtualenvs/upload-service-3zz-Lxl9/lib/python3.7/site-packages/flask/app.py", line 1952, in full_dispatch_request
rv = self.handle_user_exception(e)
File "/home/cortex/.local/share/virtualenvs/upload-service-3zz-Lxl9/lib/python3.7/site-packages/flask_restx/api.py", line 638, in error_router
return original_handler(f)
File "/home/cortex/.local/share/virtualenvs/upload-service-3zz-Lxl9/lib/python3.7/site-packages/flask/app.py", line 1821, in handle_user_exception
reraise(exc_type, exc_value, tb)
File "/home/cortex/.local/share/virtualenvs/upload-service-3zz-Lxl9/lib/python3.7/site-packages/flask/_compat.py", line 39, in reraise
raise value
File "/home/cortex/.local/share/virtualenvs/upload-service-3zz-Lxl9/lib/python3.7/site-packages/flask_restx/api.py", line 636, in error_router
return self.handle_error(e)
File "/home/cortex/.local/share/virtualenvs/upload-service-3zz-Lxl9/lib/python3.7/site-packages/flask/app.py", line 1950, in full_dispatch_request
rv = self.dispatch_request()
File "/home/cortex/.local/share/virtualenvs/upload-service-3zz-Lxl9/lib/python3.7/site-packages/flask/app.py", line 1936, in dispatch_request
return self.view_functions[rule.endpoint](**req.view_args)
File "/home/cortex/.local/share/virtualenvs/upload-service-3zz-Lxl9/lib/python3.7/site-packages/flask_restx/api.py", line 375, in wrapper
resp = resource(*args, **kwargs)
File "/home/cortex/.local/share/virtualenvs/upload-service-3zz-Lxl9/lib/python3.7/site-packages/flask/views.py", line 89, in view
return self.dispatch_request(*args, **kwargs)
File "/home/cortex/.local/share/virtualenvs/upload-service-3zz-Lxl9/lib/python3.7/site-packages/flask_restx/resource.py", line 44, in dispatch_request
resp = meth(*args, **kwargs)
File "/home/cortex/Energycortex/upload-service/app/upload/controller.py", line 37, in post
return Uploader.csv_uploader(**args)
File "/home/cortex/Energycortex/upload-service/app/upload/services/uploader.py", line 19, in csv_uploader
return CsvReader.csv_check(csv_file)
File "/home/cortex/Energycortex/upload-service/app/upload/services/processor.py", line 40, in csv_check
CsvReader.__csv_uploader(csv_json)
File "/home/cortex/Energycortex/upload-service/app/upload/services/processor.py", line 94, in __csv_uploader
db.session.bulk_insert_mappings(Upload, csv_json_response)
File "/home/cortex/.local/share/virtualenvs/upload-service-3zz-Lxl9/lib/python3.7/site-packages/sqlalchemy/orm/scoping.py", line 163, in do
return getattr(self.registry(), name)(*args, **kwargs)
File "/home/cortex/.local/share/virtualenvs/upload-service-3zz-Lxl9/lib/python3.7/site-packages/sqlalchemy/orm/session.py", line 2867, in bulk_insert_mappings
render_nulls,
File "/home/cortex/.local/share/virtualenvs/upload-service-3zz-Lxl9/lib/python3.7/site-packages/sqlalchemy/orm/session.py", line 2958, in _bulk_save_mappings
transaction.rollback(_capture_exception=True)
File "/home/cortex/.local/share/virtualenvs/upload-service-3zz-Lxl9/lib/python3.7/site-packages/sqlalchemy/util/langhelpers.py", line 69, in __exit__
exc_value, with_traceback=exc_tb,
File "/home/cortex/.local/share/virtualenvs/upload-service-3zz-Lxl9/lib/python3.7/site-packages/sqlalchemy/util/compat.py", line 182, in raise_
raise exception
File "/home/cortex/.local/share/virtualenvs/upload-service-3zz-Lxl9/lib/python3.7/site-packages/sqlalchemy/orm/session.py", line 2952, in _bulk_save_mappings
render_nulls,
File "/home/cortex/.local/share/virtualenvs/upload-service-3zz-Lxl9/lib/python3.7/site-packages/sqlalchemy/orm/persistence.py", line 102, in _bulk_insert
bookkeeping=return_defaults,
File "/home/cortex/.local/share/virtualenvs/upload-service-3zz-Lxl9/lib/python3.7/site-packages/sqlalchemy/orm/persistence.py", line 1083, in _emit_insert_statements
c = cached_connections[connection].execute(statement, multiparams)
File "/home/cortex/.local/share/virtualenvs/upload-service-3zz-Lxl9/lib/python3.7/site-packages/sqlalchemy/engine/base.py", line 1011, in execute
return meth(self, multiparams, params)
File "/home/cortex/.local/share/virtualenvs/upload-service-3zz-Lxl9/lib/python3.7/site-packages/sqlalchemy/sql/elements.py", line 298, in _execute_on_connection
return connection._execute_clauseelement(self, multiparams, params)
File "/home/cortex/.local/share/virtualenvs/upload-service-3zz-Lxl9/lib/python3.7/site-packages/sqlalchemy/engine/base.py", line 1130, in _execute_clauseelement
distilled_params,
File "/home/cortex/.local/share/virtualenvs/upload-service-3zz-Lxl9/lib/python3.7/site-packages/sqlalchemy/engine/base.py", line 1317, in _execute_context
e, statement, parameters, cursor, context
File "/home/cortex/.local/share/virtualenvs/upload-service-3zz-Lxl9/lib/python3.7/site-packages/sqlalchemy/engine/base.py", line 1511, in _handle_dbapi_exception
sqlalchemy_exception, with_traceback=exc_info[2], from_=e
File "/home/cortex/.local/share/virtualenvs/upload-service-3zz-Lxl9/lib/python3.7/site-packages/sqlalchemy/util/compat.py", line 182, in raise_
raise exception
File "/home/cortex/.local/share/virtualenvs/upload-service-3zz-Lxl9/lib/python3.7/site-packages/sqlalchemy/engine/base.py", line 1257, in _execute_context
cursor, statement, parameters, context
File "/home/cortex/.local/share/virtualenvs/upload-service-3zz-Lxl9/lib/python3.7/site-packages/sqlalchemy/dialects/postgresql/psycopg2.py", line 873, in do_executemany
cursor.executemany(statement, parameters)
sqlalchemy.exc.IntegrityError: (psycopg2.errors.NotNullViolation) null value in column "timestamp" violates not-null constraint
DETAIL: Failing row contains (6, null, null).
[SQL: INSERT INTO "user_uploaded_CSV" DEFAULT VALUES]
[parameters: ({}, {}, {}, {}, {}, {}, {}, {})]
(Background on this error at: http://sqlalche.me/e/13/gkpj)
我做错了什么？任何帮助表示赞赏。
【问题讨论】：
标签： python-3.x flask sqlalchemy flask-sqlalchemy psycopg2