`omop.db_manager`

source

The db_manager.py module provides utilities for managing database connections to a PostgreSQL database hosting OMOP data tables. It creates a secure connection using environment variables and offers a context manager for safe session handling with SQLAlchemy.

Functions

`get_db_connection`

Retrieves database connection parameters from environment variables and constructs a PostgreSQL connection URI.

Environmental variables

Variable	Description
`DB_HOST`	Database server hostname or IP address
`DB_USER`	Database username for authentication
`DB_PASSWORD`	Database password for authentication
`DB_NAME`	Name of the database to connect to
`DB_PORT`	Port number for database connection
`DB_SCHEMA`	Schema name containing the OMOP tables

Returns

Dictionary containing:
- uri: Complete PostgreSQL connection URI for SQL Alchemy
- schema: Database schema name

`get_session`

Context manager that provides a database session and ensures it is properly closed after use. It ensures timely release of database connections back to the connection pool, improving application scalability.

Returns

A SQLAlchemy session object that can be used to execute database queries

Module Variables

engine (sqlalchemy.engine.base.Engine): SQLAlchemy engine instance configured with the connection URI
db_session (sqlalchemy.orm.session.sessionmaker): SQLAlchemy sessionmaker configured with the engine

OMOP OMOP match