I have MS Access DB file (.accdb) from my client and need to describe tables and columns with declarative_base class. As I can see in table constructor – one of column has Integer value and has …
I have MS Access DB file (.accdb) from my client and need to describe tables and columns with declarative_base class. As I can see in table constructor – one of column has Integer value and has …
So I’m using sqlalchemy for a project I’m working on. I’ve got an issue where I will eventually have thousands of records that need to be saved every hour. These records may be inserted or updated. I’…
I am developing a web application with Flask, Python, SQLAlchemy, and Mysql. I have 2 tables: TaskUser: – id – id_task (foreign key of id column of table Task) – message Task – id – id_type_task I …
I use SQLAlchemy 1.4.0beta1 and enabled future flag for both the engine and the Session. Normally I don’t receive warnings. But in debug mode I receive warnings on 2.0 style select statements. My …
I’m trying to dump a pandas DataFrame into an existing Snowflake table (via a jupyter notebook). When I run the code below no errors are raised, but no data is written to the destination SF table (df …
One of our queries that was working in Python 2 + mxODBC is not working in Python 3 + pyodbc; it raises an error like this: Maximum number of parameters in the sql query is 2100. while connecting to SQL Server. Since both the printed queries have 3000 params, I thought it should fail in both environments, but clearly that doesn’t seem to be the case here. In the Python 2 environment, both MSODBC 11 or MSODBC 17 works, so I immediately ruled out a driver related issue. So my question is: Is it correct to send a list as
I’m creating the engine and the Metadata as follows Yields AttributeError: packages, and dir(Base.classes) returns no attributes with that name, neither with the orders name. Taking the only=[‘orders’, ‘packages’] off makes it reflect only a few random tables. Now, when using the inspector that comes with native SQLAlchemy the table actually works (link to documentation): Is this a bug, or am I overlooking something here? Thanks! Installed package versions: Answer SQLAlchemy’s automap extension only reflects tables which have defined primary keys. From the note in the docs: […] for a table to be mapped, it must specify a primary key.
I’m working on a project that uses FastAPI alongside Pydantic and SQLAlchemy. I’m also using encode/databases to manage database connections. But for some weird reason, I get asyncpg.exceptions.DataError: invalid input for query argument $1: 217027642536 (value out of int32 range) anytime I try saving to the database. Here’s what my code looks like: database.py database_manager.py endpoints.py models.py services.py I can’t see anything wrong with this. Someone, please tell me what the hell is going on? Answer You are basically having Integer Overflow, Int32 represents 2^31 – 1, that means it can store the values in range -2147483648 to 2147483648 but
I am writing an app in python flask-sqlalchemy with MySQL DB (https://flask-sqlalchemy.palletsprojects.com/en/2.x/) and I am wondering if I have to make “db.session.commit() or db.session.rollback()” after GET call, which only query DB . For example: Answer orders = Order.query.all() is a SELECT query that could be extended to include additional filters (WHERE etc.). It doesn’t alter the database, it simply reads values from it. You don’t need to commit on a read for precisely that reason – what would you store other than “I just read this data”? Databases are concerned about this in other ways i.e. access permissions and logs.
I can successfully connect my python notebook with sql server this way : Let’s take this sample dataframe : I have a sql table with the same columns, named table_name. Objective : I want to delete in table_name all the rows where a row in df has the same Name, same Date, same Status, and Max = 0 (only in table_name, not necessary in df) I tried the following but it doesn’t work : Could you please help me to understand what is wrong ? Answer Different libraries use different symbols for their placeholders. The one you are using apparently