Backend finished

Co-authored-by: Álvaro <alvaro6gv@users.noreply.github.com>

backend/app/db/database.py

@@ -0,0 +1,18 @@
+from sqlalchemy import create_engine
+from sqlalchemy.orm import sessionmaker, declarative_base
+from app.core.config import settings
+
+engine = create_engine(
+    settings.DB_URL,
+    pool_pre_ping=True,
+)
+
+SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
+Base = declarative_base()
+
+def get_db():
+    db = SessionLocal()
+    try:
+        yield db
+    finally:
+        db.close()