Database Configuration
======================

Database connection and session management.

.. automodule:: ai4drpm.db.database
   :members:
   :undoc-members:
   :show-inheritance:

Overview
--------

This module provides database configuration and session management:

Key Components
--------------

Database URL
~~~~~~~~~~~~

Configurable database connection string supporting:

* PostgreSQL (production)
* SQLite (development/testing)
* Connection pooling configuration

SessionLocal
~~~~~~~~~~~~

SQLAlchemy session factory:

.. code-block:: python

    from ai4drpm.db.database import SessionLocal

    db = SessionLocal()
    try:
        # Database operations
        pass
    finally:
        db.close()

get_db Dependency
~~~~~~~~~~~~~~~~~

FastAPI dependency for database sessions:

.. code-block:: python

    from ai4drpm.db.database import get_db
    from fastapi import Depends

    @app.get("/resources")
    def get_resources(db: Session = Depends(get_db)):
        # db session automatically managed
        pass

Engine Configuration
~~~~~~~~~~~~~~~~~~~~

SQLAlchemy engine with:

* Connection pooling (pool_size, max_overflow)
* Connection timeout settings
* Echo mode for SQL logging (development)
* Pool pre-ping for connection health checks

Features
--------

* **Connection Pooling**: Efficient connection reuse
* **Automatic Session Management**: Context managers for proper cleanup
* **Transaction Support**: Commit/rollback handling
* **Health Checks**: Connection validation
* **Migration Support**: Alembic integration

Usage Example
-------------

.. code-block:: python

    from ai4drpm.db.database import SessionLocal, engine, Base

    # Create all tables
    Base.metadata.create_all(bind=engine)

    # Use session
    db = SessionLocal()
    try:
        # Perform operations
        result = db.query(User).all()
        db.commit()
    except Exception:
        db.rollback()
        raise
    finally:
        db.close()

    # Or use as context manager
    with SessionLocal() as db:
        result = db.query(User).all()