Using cdecimal in SQLAlchemy

Question

So I'm trying to use cdecimal to store monetary values in my database. SQLAlchemy Doc

import sys
import cdecimal
sys.modules["decimal"] = cdecimal

I've connected my PostgreSQL database like so:

sqlalchemy.url = postgresql+psycopg2://user:password@host:port/dbname

I've set up the model something like this:

class Exchange(Base):
    amount = Column(Numeric)
    ...

    def __init__(self, amount):
        self.amount = cdecimal.Decimal(amount)

However, whenever I do this, I get the following error:

ProgrammingError: (ProgrammingError) can't adapt type 'cdecimal.Decimal' 'INSERT INTO...

What am I doing wrong?

Answer 1

This one is working for me please try this

import sys 
import cdecimal
sys.modules["decimal"] = cdecimal

from sqlalchemy import create_engine, Numeric, Integer, Column
from sqlalchemy.ext.declarative import declarative_base

engine = create_engine('mysql://test:test@localhost/test1')
Base = declarative_base()


class Exchange(Base):
    __tablename__ = 'exchange'
    id = Column(Integer, primary_key=True)
    amount = Column(Numeric(10,2))

    def __init__(self, amount):
        self.amount = cdecimal.Decimal(amount)


Base.metadata.create_all(engine)
from sqlalchemy.orm import sessionmaker
Session = sessionmaker(bind=engine)
session = Session()


x = Exchange(10.5)
session.add(x)
session.commit()

Note: I dont have pgsql in my pc so I tried on mysql.