Add database utility

Author: JoshCap20

database.py

@@ -0,0 +1,28 @@
+"""SQLAlchemy DB Engine for FastAPI dependency injection."""
+
+import sqlalchemy
+from sqlalchemy.orm import Session
+from settings import getenv
+
+
+def _engine_str(name: str = getenv("DB_NAME")) -> str:
+    """Helper function for reading settings from environment variables to produce connection string."""
+    dialect = "postgresql+psycopg2"
+    user = getenv("DB_USERNAME")
+    password = getenv("DB_PASSWORD")
+    host = getenv("DB_HOST")
+    port = getenv("DB_PORT")
+    return f"{dialect}://{user}:{password}@{host}:{port}/{name}"
+
+
+engine = sqlalchemy.create_engine(_engine_str(), echo=True)
+"""Application-level SQLAlchemy database engine."""
+
+
+def db_session():
+    """Generator function offering dependency injection of SQLAlchemy Sessions."""
+    session = Session(engine)
+    try:
+        yield session
+    finally:
+        session.close()