Step 3：Study / Site / StudyMember + 项目权限

backend/app/crud/site.py

@@ -0,0 +1,48 @@
+import uuid
+from typing import Sequence
+
+from sqlalchemy import select, update
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.models.site import Site
+from app.schemas.site import SiteCreate, SiteUpdate
+
+
+async def create_site(db: AsyncSession, study_id: uuid.UUID, site_in: SiteCreate) -> Site:
+    site = Site(
+        study_id=study_id,
+        name=site_in.name,
+        city=site_in.city,
+        pi_name=site_in.pi_name,
+        contact=site_in.contact,
+        is_active=site_in.is_active,
+    )
+    db.add(site)
+    await db.commit()
+    await db.refresh(site)
+    return site
+
+
+async def get_site(db: AsyncSession, site_id: uuid.UUID) -> Site | None:
+    result = await db.execute(select(Site).where(Site.id == site_id))
+    return result.scalar_one_or_none()
+
+
+async def update_site(db: AsyncSession, site: Site, site_in: SiteUpdate) -> Site:
+    update_data = site_in.model_dump(exclude_unset=True)
+    if update_data:
+        await db.execute(
+            update(Site)
+            .where(Site.id == site.id)
+            .values(**update_data)
+        )
+        await db.commit()
+    await db.refresh(site)
+    return site
+
+
+async def list_by_study(db: AsyncSession, study_id: uuid.UUID, skip: int = 0, limit: int = 100) -> Sequence[Site]:
+    result = await db.execute(
+        select(Site).where(Site.study_id == study_id).offset(skip).limit(limit)
+    )
+    return result.scalars().all()