SQLAlchemy-Catalyst

SQLAlchemy-Catalyst is a collection of helper methods for base SQLAlchemy classes.

Installation

You can install the package using pip:

pip install SQLAlchemy-Catalyst

Usage

Importing

database.py:

from SQLAlchemy_Catalyst import Catalyst
from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker

engine = create_engine('sqlite:///example.db')
Session = sessionmaker(bind=engine)

class ExampleModel(Catalyst):
  __tablename__ = 'example_table'

  id = Column(Integer, primary_key=True)
  name = Column(String(50))
  age = Column(Integer)

Implementing

implementation.py:

from database import ExampleModel, Session
example = ExampleModel(name='John', age=30)
session = Session()
session.add(example)
session.commit()

# Call the methods on the example instance
example.add_if_new(session, ['name'], {'name': 'Mary'})
example.add_or_update(session, {'name': 'Mary'}, {'age': 40})
example.update_if_empty(session, {'name': 'Mary'}, {'age': 40})
example.merge_records_attributes(session, {'name': 'Mary'}, {'age': 40})
example.bulk_upsert(session, {'name': 'Mary'}, {'age': 40})
example.increment_column(session, {'name': 'Mary'}, 'age', 10)
example.decrement_column(session, {'name': 'Mary'}, 'age', 5)

Methods available

add_if_new(session, column_names, values)

Adds a new record to the database if no record exists with the provided values.

• session: An active database session object.
• column_names: A list of column names that need to be checked.
• values: A dictionary of column names and values to be added.

add_or_update(session, filters, values)

Adds a new record to the database or updates an existing record.

• session: An active database session object.
• filters: A dictionary of column names and values to be checked for an existing record.
• values: A dictionary of column names and values to be added/updated.

update_if_empty(session, filters, values)

Updates an existing record in the database if the specified columns are empty.

• session: An active database session object.
• filters: A dictionary of column names and values to be checked for an existing record.
• values: A dictionary of column names and values to be updated.

merge_records_attributes(session, filters, values)

Merges the attributes of two records into one.

• session: An active database session object.
• filters: A dictionary of column names and values to be checked for an existing record.
• values: A dictionary of column names and values to be merged.

bulk_upsert(session, filters, values)

Updates existing records in the database or inserts new records.

• session: An active database session object.
• filters: A dictionary of column names and values to be checked for existing records.
• values: A dictionary of column names and values to be updated/added.

increment_column(session, filters, column_name, value)

Increments a numeric column in an existing record.

• session: An active database session object.
• filters: A dictionary of column names and values to be checked for an existing record.
• column_name: The name of the numeric column to be incremented.
• value: The value to increment the column by (default is 1).

decrement_column(session, filters, column_name, value)

Decrements a numeric column in an existing record.

• session: An active database session object.
• filters: A dictionary of column names and values to be checked for an existing record.
• column_name: The name of the numeric column to be decremented.
• value: The value to decrement the column by (default is 1).

License

This project is licensed under the MIT License - see the LICENSE file for details.