Initial commit: yu-zhi-ran platform with automation integration

platform/backend/app/database.py

@@ -0,0 +1,28 @@
+from sqlalchemy import create_engine
+from sqlalchemy.ext.declarative import declarative_base
+from sqlalchemy.orm import sessionmaker
+import os
+from pathlib import Path
+
+# 计算项目根目录（backend/app/database.py -> yu-zhi-ran）
+# __file__: platform/backend/app/database.py
+# parents[0]=app, [1]=backend, [2]=platform, [3]=yu-zhi-ran
+PROJECT_ROOT = Path(__file__).resolve().parents[3]
+DATA_DIR = os.getenv('DATA_DIR', str(PROJECT_ROOT / 'data'))
+os.makedirs(DATA_DIR, exist_ok=True)
+DB_PATH = os.path.join(DATA_DIR, 'yzr.db')
+SQLALCHEMY_DATABASE_URL = f"sqlite:///{DB_PATH}"
+
+engine = create_engine(SQLALCHEMY_DATABASE_URL, connect_args={"check_same_thread": False})
+SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
+Base = declarative_base()
+
+def init_db():
+    Base.metadata.create_all(bind=engine)
+
+def get_db():
+    db = SessionLocal()
+    try:
+        yield db
+    finally:
+        db.close()