Tag: database-cursor

How to add a cursor() of a db connection to a sqlalchemy.orm session? “sqlalchemy.orm.exc.UnmappedInstanceError: Class ‘builtins.int’ is not mapped”

autoflush database-connection database-cursor python sqlalchemy

I am in a Ubuntu 22.04 Docker container with Python 3.10. I use these apt packages: I use the following Python packages: The sessionmaker parameter autoflush is set to True. I want to add a deletion and after that an insertion to a sqlalchemy.orm session so that I commit only when the two commands worked out well. The aim of

multiple execute on a single connection.cursor in django. Is it safe?

database-connection database-cursor django django-database python

I am opening a cursor with connection.cursor executing a bunch of deletes then closing the cursor. It works, but I am not sure if it has any side effect. Would appreciate any feedback. Answer Since you are not executing these SQL statements in the transaction, you may encounter confusing states (for example, data was deleted from table_a, but not from

Output pyodbc cursor results as python dictionary

database-cursor dictionary pyodbc pypyodbc python

How do I serialize pyodbc cursor output (from .fetchone, .fetchmany or .fetchall) as a Python dictionary? I’m using bottlepy and need to return dict so it can return it as JSON. Answer If you don’t know columns ahead of time, use Cursor.description to build a list of column names and zip with each row to produce a list of dictionaries.

About mysql cursor and iterator

database-cursor fetchall mysql python

Imagine I have a mysql cursor and data read. The amount of data might be very big that I want to deal with one line each time. An easy and straight forward way might be like this: But this doesn’t look good, so I wonder whether this way works as imagined: The thing I want to know is: if I