EnORM

EnORM---EnDATA Object Relational Mapper.

Features

• Model Definition:
  • Define database tables using Python classes.
  • Support for primary keys, foreign keys, constraints, and default values.
• Type System:
  • Use Python-native types for columns with support for custom SQL-compatible types.
  • Full support for PostgreSQL, MySQL, SQLite, Oracle, and SQL Server backends with in-house types.
• Query Building:
  • Pythonic API for constructing queries.
  • Filtering, joining, grouping, ordering, and aggregation.
  • Ability to use Python expressions directly in queries.
• Subquerying:
  • Full support for subqueries as nested or derived tables.
  • Essential for advanced query composition and reusable query fragments.
• Relationships:
  • Define one-to-many and many-to-many relationships.
  • Cascading updates and deletes for referential integrity.
• Transactions:
  • Transaction management with commit and rollback control.
• Database Session:
  • Manage database interactions with a session.
  • Context manager support for secure and efficient operations.
• Connection Pooling:
  • Thread-safe connection management with pooling for performance.
• Schema Management:
  • Automatic SQL generation for table creation.
• Custom Functions and Aggregates:
  • Built-in support for SQL functions and aggregates, extensible for complex operations.
• Data Validation:
  • Automatic enforcement of field types and constraints during record creation and updates.
• Custom Exceptions:
  • Comprehensive exceptions for debugging and error reporting.

Installation

EnORM is a PyPI-indexed library. You can install it by running:

pip install EnORM

EnORM supports Python 3.10+.

Example Usage

from EnORM import CASCADE, Column, DBEngine, DBSession, Float, ForeignKey, Integer, Model, Serial, String


class Company(Model):
    __table__ = "companies"

    id = Column(Serial, primary_key=True)
    name = Column(String, nullable=False)
    country = Column(String, 40)


class Employee(Model):
    id = Column(Serial, primary_key=True)
    full_name = Column(String, 100, nullable=False)
    salary = Column(Float)
    age = Column(Integer)
    role = Column(String, 20, default="entry")
    company_id = Column(Serial, None, ForeignKey(Company, reverse_name="employees", on_delete=CASCADE))


eng = DBEngine("postgresql://user:secret@localhost:5432/my_db", pool_size=64)
with DBSession(eng) as session:
    the_company = session.query(Company).filter(Company.country == "United Kingdom").first()

    new_employee = Employee(full_name="Nima Bavari Goudarzi", salary=64320.00, role="engineer", company_id=the_company.id)
    session.add(new_employee)
    
    sharks = session.query(Employee, Employee.full_name, Employee.company_id).filter(Employee.salary > 90000.00).all()

Documentation

See full documentation.

Dev Scripts

Set Up Dev Environment

Run:

make set_dev_env

to set up the dev environment.

This sets:

• git pre-commit hook

If you intend to touch the code, set up dev environment first.

Linting and Formatting

Run:

make cleanup

to run linting, formatting, typechecking, and automatically updating the documentation.

Testing

Run:

make test

to start the tests.