From 8f27794da6179f6b734cb3e4d586e9021c03d03a Mon Sep 17 00:00:00 2001
From: GinHa <15201596918@163.com>
Date: Wed, 3 Jun 2026 14:15:21 +0800
Subject: [PATCH] =?UTF-8?q?=E4=BF=AE=E5=A4=8Dscalar=5Fone=5For=5Fnone?=
 =?UTF-8?q?=E7=9B=B8=E5=85=B3limit?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 video-gen-api/app/api/v1/admin.py             | 38 ++++++++++---------
 video-gen-api/app/api/v1/auth.py              |  4 +-
 video-gen-api/app/api/v1/generation.py        |  4 ++
 video-gen-api/app/api/v1/generation_ai.py     |  3 ++
 video-gen-api/app/api/v1/menu_configs.py      |  4 +-
 video-gen-api/app/api/v1/payments.py          |  5 ++-
 video-gen-api/app/api/v1/projects.py          |  1 +
 video-gen-api/app/api/v1/recharge_packages.py |  4 +-
 video-gen-api/app/dependencies.py             |  2 +-
 video-gen-api/app/main.py                     | 14 ++++---
 video-gen-api/app/services/auth.py            |  4 +-
 video-gen-api/app/services/credits.py         |  8 ++--
 .../app/services/generation_ai_service.py     |  4 +-
 .../services/generation_billing_service.py    |  2 +-
 .../services/generation_provider_service.py   |  4 +-
 video-gen-api/app/services/llm.py             |  2 +-
 video-gen-api/app/services/notification.py    |  3 +-
 video-gen-api/app/services/payment.py         |  2 +-
 .../services/resource_accounting_service.py   |  3 +-
 video-gen-api/app/services/video_queue.py     |  1 +
 video-gen-api/app/services/video_url.py       |  1 +
 .../app/tasks/generation_create_tasks.py      |  4 +-
 .../app/tasks/generation_download_tasks.py    |  4 +-
 .../app/tasks/generation_poll_tasks.py        |  4 +-
 24 files changed, 73 insertions(+), 52 deletions(-)

diff --git a/video-gen-api/app/api/v1/admin.py b/video-gen-api/app/api/v1/admin.py
index acf799f8..26ca72ae 100644
--- a/video-gen-api/app/api/v1/admin.py
+++ b/video-gen-api/app/api/v1/admin.py
@@ -97,18 +97,18 @@ async def create_user(
     if req.user_type == "frontend":
         if not req.phone:
             raise HTTPException(status_code=400, detail="前台用户必须填写手机号")
-        existing_phone = await db.execute(select(User).where(User.phone == req.phone))
+        existing_phone = await db.execute(select(User).where(User.phone == req.phone).limit(1))
         if existing_phone.scalar_one_or_none():
             raise HTTPException(status_code=400, detail="该手机号已注册")
         username = f"用户{req.phone[-4:]}"
-        existing_name = await db.execute(select(User).where(User.username == username))
+        existing_name = await db.execute(select(User).where(User.username == username).limit(1))
         if existing_name.scalar_one_or_none():
             username = f"用户{req.phone[-4:]}{random.randint(10, 99)}"
     else:
         if not req.username:
             raise HTTPException(status_code=400, detail="后台用户必须填写用户名")
         username = req.username
-        existing = await db.execute(select(User).where(User.username == username))
+        existing = await db.execute(select(User).where(User.username == username).limit(1))
         if existing.scalar_one_or_none():
             raise HTTPException(status_code=400, detail="用户名已存在")
 
@@ -137,7 +137,7 @@ async def update_user_menus(
     admin: User = Depends(get_admin_user),
     db: AsyncSession = Depends(get_db),
 ):
-    result = await db.execute(select(User).where(User.id == user_id))
+    result = await db.execute(select(User).where(User.id == user_id).limit(1))
     user = result.scalar_one_or_none()
     if not user:
         raise HTTPException(status_code=404, detail="用户不存在")
@@ -153,7 +153,7 @@ async def get_user(
     admin: User = Depends(get_admin_user),
     db: AsyncSession = Depends(get_db),
 ):
-    result = await db.execute(select(User).where(User.id == user_id))
+    result = await db.execute(select(User).where(User.id == user_id).limit(1))
     user = result.scalar_one_or_none()
     if not user:
         raise HTTPException(status_code=404, detail="用户不存在")
@@ -204,7 +204,7 @@ async def reset_user_password(
     admin: User = Depends(get_admin_user),
     db: AsyncSession = Depends(get_db),
 ):
-    result = await db.execute(select(User).where(User.id == user_id))
+    result = await db.execute(select(User).where(User.id == user_id).limit(1))
     user = result.scalar_one_or_none()
     if not user:
         raise HTTPException(status_code=404, detail="用户不存在")
@@ -356,7 +356,7 @@ async def delete_admin_notification(
     db: AsyncSession = Depends(get_db),
 ):
     result = await db.execute(
-        select(Notification).where(Notification.id == notification_id)
+        select(Notification).where(Notification.id == notification_id).limit(1)
     )
     notif = result.scalar_one_or_none()
     if not notif:
@@ -418,6 +418,7 @@ async def update_payment_config(
             SystemConfig.id == config_id,
             SystemConfig.key.like("payment_%"),
         )
+        .limit(1)
     )
     config = result.scalar_one_or_none()
     if not config:
@@ -497,7 +498,7 @@ async def update_industry_config(
     db: AsyncSession = Depends(get_db),
 ):
     result = await db.execute(
-        select(IndustryConfig).where(IndustryConfig.id == config_id)
+        select(IndustryConfig).where(IndustryConfig.id == config_id).limit(1)
     )
     config = result.scalar_one_or_none()
     if not config:
@@ -520,7 +521,7 @@ async def delete_industry_config(
     db: AsyncSession = Depends(get_db),
 ):
     result = await db.execute(
-        select(IndustryConfig).where(IndustryConfig.id == config_id)
+        select(IndustryConfig).where(IndustryConfig.id == config_id).limit(1)
     )
     config = result.scalar_one_or_none()
     if not config:
@@ -563,7 +564,7 @@ async def update_video_engine(
     db: AsyncSession = Depends(get_db),
 ):
     result = await db.execute(
-        select(VideoEngine).where(VideoEngine.id == engine_id)
+        select(VideoEngine).where(VideoEngine.id == engine_id).limit(1)
     )
     engine = result.scalar_one_or_none()
     if not engine:
@@ -581,7 +582,7 @@ async def delete_video_engine(
     db: AsyncSession = Depends(get_db),
 ):
     result = await db.execute(
-        select(VideoEngine).where(VideoEngine.id == engine_id)
+        select(VideoEngine).where(VideoEngine.id == engine_id).limit(1)
     )
     engine = result.scalar_one_or_none()
     if not engine:
@@ -624,7 +625,7 @@ async def update_image_engine(
     db: AsyncSession = Depends(get_db),
 ):
     result = await db.execute(
-        select(ImageEngine).where(ImageEngine.id == engine_id)
+        select(ImageEngine).where(ImageEngine.id == engine_id).limit(1)
     )
     engine = result.scalar_one_or_none()
     if not engine:
@@ -642,7 +643,7 @@ async def delete_image_engine(
     db: AsyncSession = Depends(get_db),
 ):
     result = await db.execute(
-        select(ImageEngine).where(ImageEngine.id == engine_id)
+        select(ImageEngine).where(ImageEngine.id == engine_id).limit(1)
     )
     engine = result.scalar_one_or_none()
     if not engine:
@@ -711,7 +712,7 @@ async def update_credit_ratio(
     db: AsyncSession = Depends(get_db),
 ):
     result = await db.execute(
-        select(CreditRatio).where(CreditRatio.id == ratio_id)
+        select(CreditRatio).where(CreditRatio.id == ratio_id).limit(1)
     )
     ratio = result.scalar_one_or_none()
     if not ratio:
@@ -733,7 +734,7 @@ async def delete_credit_ratio(
     db: AsyncSession = Depends(get_db),
 ):
     result = await db.execute(
-        select(CreditRatio).where(CreditRatio.id == ratio_id)
+        select(CreditRatio).where(CreditRatio.id == ratio_id).limit(1)
     )
     ratio = result.scalar_one_or_none()
     if not ratio:
@@ -790,7 +791,7 @@ async def update_model_config(
     admin: User = Depends(get_admin_user),
     db: AsyncSession = Depends(get_db),
 ):
-    result = await db.execute(select(ModelConfig).where(ModelConfig.id == config_id))
+    result = await db.execute(select(ModelConfig).where(ModelConfig.id == config_id).limit(1))
     config = result.scalar_one_or_none()
     if not config:
         raise HTTPException(status_code=404, detail="配置不存在")
@@ -806,7 +807,7 @@ async def delete_model_config(
     admin: User = Depends(get_admin_user),
     db: AsyncSession = Depends(get_db),
 ):
-    result = await db.execute(select(ModelConfig).where(ModelConfig.id == config_id))
+    result = await db.execute(select(ModelConfig).where(ModelConfig.id == config_id).limit(1))
     config = result.scalar_one_or_none()
     if not config:
         raise HTTPException(status_code=404, detail="配置不存在")
@@ -833,7 +834,7 @@ async def update_system_config(
     admin: User = Depends(get_admin_user),
     db: AsyncSession = Depends(get_db),
 ):
-    result = await db.execute(select(SystemConfig).where(SystemConfig.id == config_id))
+    result = await db.execute(select(SystemConfig).where(SystemConfig.id == config_id).limit(1))
     config = result.scalar_one_or_none()
     if not config:
         raise HTTPException(status_code=404, detail="配置不存在")
@@ -1053,6 +1054,7 @@ async def admin_update_generation_status(
             GenerationRecord.id == record_id,
             GenerationRecord.deleted_at.is_(None),
         )
+        .limit(1)
     )
     record = result.scalar_one_or_none()
     if not record:
diff --git a/video-gen-api/app/api/v1/auth.py b/video-gen-api/app/api/v1/auth.py
index 1cf8ca40..1f309877 100644
--- a/video-gen-api/app/api/v1/auth.py
+++ b/video-gen-api/app/api/v1/auth.py
@@ -78,7 +78,7 @@ async def register(req: RegisterRequest, db: AsyncSession = Depends(get_db)):
         )
 
     # Check if phone already registered
-    existing = await db.execute(select(User).where(User.phone == req.phone))
+    existing = await db.execute(select(User).where(User.phone == req.phone).limit(1))
     if existing.scalar_one_or_none():
         from fastapi import HTTPException, status
         raise HTTPException(
@@ -89,7 +89,7 @@ async def register(req: RegisterRequest, db: AsyncSession = Depends(get_db)):
     # Create user with default username: 用户 + last 4 digits of phone
     import random
     username = f"用户{req.phone[-4:]}"
-    existing_name = await db.execute(select(User).where(User.username == username))
+    existing_name = await db.execute(select(User).where(User.username == username).limit(1))
     if existing_name.scalar_one_or_none():
         username = f"用户{req.phone[-4:]}{random.randint(10, 99)}"
 
diff --git a/video-gen-api/app/api/v1/generation.py b/video-gen-api/app/api/v1/generation.py
index c796d196..b157217a 100644
--- a/video-gen-api/app/api/v1/generation.py
+++ b/video-gen-api/app/api/v1/generation.py
@@ -228,6 +228,7 @@ async def optimize(
             Project.user_id == current_user.id,
             Project.deleted_at.is_(None),
         )
+        .limit(1)
     )
     project = proj_result.scalar_one_or_none()
     if not project:
@@ -460,6 +461,7 @@ async def update_prompt(
             GenerationRecord.user_id == current_user.id,
             GenerationRecord.deleted_at.is_(None),
         )
+        .limit(1)
     )
     record = result.scalar_one_or_none()
     if not record:
@@ -505,6 +507,7 @@ async def get_queue_status(
             GenerationRecord.user_id == current_user.id,
             GenerationRecord.deleted_at.is_(None),
         )
+        .limit(1)
     )
     record = result.scalar_one_or_none()
     if not record:
@@ -548,6 +551,7 @@ async def seedance_callback(request: Request, db: AsyncSession = Depends(get_db)
             GenerationRecord.seedance_task_id == task_id,
             GenerationRecord.deleted_at.is_(None),
         )
+        .limit(1)
     )
     record = result.scalar_one_or_none()
     if not record:
diff --git a/video-gen-api/app/api/v1/generation_ai.py b/video-gen-api/app/api/v1/generation_ai.py
index 4ead2651..1aaebcca 100644
--- a/video-gen-api/app/api/v1/generation_ai.py
+++ b/video-gen-api/app/api/v1/generation_ai.py
@@ -416,6 +416,7 @@ async def get_task(
             ChatGenerationTask.generation_mode == "chatapi_async",
             ChatGenerationTask.deleted_at.is_(None),
         )
+        .limit(1)
     )
     task = result.scalar_one_or_none()
     if not task:
@@ -464,6 +465,7 @@ async def delete_task(
             ChatGenerationTask.generation_mode == "chatapi_async",
             ChatGenerationTask.deleted_at.is_(None),
         )
+        .limit(1)
     )
     task = result.scalar_one_or_none()
     if not task:
@@ -536,6 +538,7 @@ async def retry_task(
             ChatGenerationTask.generation_mode == "chatapi_async",
             ChatGenerationTask.deleted_at.is_(None),
         )
+        .limit(1)
     )
     task = result.scalar_one_or_none()
     if not task:
diff --git a/video-gen-api/app/api/v1/menu_configs.py b/video-gen-api/app/api/v1/menu_configs.py
index 0950ce1a..44794a57 100644
--- a/video-gen-api/app/api/v1/menu_configs.py
+++ b/video-gen-api/app/api/v1/menu_configs.py
@@ -65,7 +65,7 @@ async def update_menu_config(
     admin: User = Depends(get_admin_user),
     db: AsyncSession = Depends(get_db),
 ):
-    result = await db.execute(select(MenuConfig).where(MenuConfig.id == menu_id))
+    result = await db.execute(select(MenuConfig).where(MenuConfig.id == menu_id).limit(1))
     menu = result.scalar_one_or_none()
     if not menu:
         from fastapi import HTTPException, status
@@ -82,7 +82,7 @@ async def delete_menu_config(
     admin: User = Depends(get_admin_user),
     db: AsyncSession = Depends(get_db),
 ):
-    result = await db.execute(select(MenuConfig).where(MenuConfig.id == menu_id))
+    result = await db.execute(select(MenuConfig).where(MenuConfig.id == menu_id).limit(1))
     menu = result.scalar_one_or_none()
     if not menu:
         from fastapi import HTTPException, status
diff --git a/video-gen-api/app/api/v1/payments.py b/video-gen-api/app/api/v1/payments.py
index bbb76a30..6b2d8ca4 100644
--- a/video-gen-api/app/api/v1/payments.py
+++ b/video-gen-api/app/api/v1/payments.py
@@ -23,6 +23,7 @@ async def recharge(
             RechargePackage.id == req.plan,
             RechargePackage.is_active == True,
         )
+        .limit(1)
     )
     pkg = result.scalar_one_or_none()
     if not pkg:
@@ -45,7 +46,7 @@ async def wechat_callback(request: Request, db: AsyncSession = Depends(get_db)):
         raise HTTPException(status_code=400, detail="签名验证失败")
     order_no = data.get("out_trade_no")
     result = await db.execute(
-        select(PaymentOrder).where(PaymentOrder.order_no == order_no)
+        select(PaymentOrder).where(PaymentOrder.order_no == order_no).limit(1)
     )
     order = result.scalar_one_or_none()
     if order:
@@ -60,7 +61,7 @@ async def alipay_callback(request: Request, db: AsyncSession = Depends(get_db)):
         raise HTTPException(status_code=400, detail="签名验证失败")
     order_no = data.get("out_trade_no")
     result = await db.execute(
-        select(PaymentOrder).where(PaymentOrder.order_no == order_no)
+        select(PaymentOrder).where(PaymentOrder.order_no == order_no).limit(1)
     )
     order = result.scalar_one_or_none()
     if order:
diff --git a/video-gen-api/app/api/v1/projects.py b/video-gen-api/app/api/v1/projects.py
index c0244d8f..56473f5e 100644
--- a/video-gen-api/app/api/v1/projects.py
+++ b/video-gen-api/app/api/v1/projects.py
@@ -60,6 +60,7 @@ async def delete_project(
             Project.user_id == current_user.id,
             Project.deleted_at.is_(None),
         )
+        .limit(1)
     )
     project = result.scalar_one_or_none()
     if not project:
diff --git a/video-gen-api/app/api/v1/recharge_packages.py b/video-gen-api/app/api/v1/recharge_packages.py
index ba737efa..acc82560 100644
--- a/video-gen-api/app/api/v1/recharge_packages.py
+++ b/video-gen-api/app/api/v1/recharge_packages.py
@@ -77,7 +77,7 @@ async def update_package(
     db: AsyncSession = Depends(get_db),
 ):
     result = await db.execute(
-        select(RechargePackage).where(RechargePackage.id == pkg_id)
+        select(RechargePackage).where(RechargePackage.id == pkg_id).limit(1)
     )
     pkg = result.scalar_one_or_none()
     if not pkg:
@@ -95,7 +95,7 @@ async def delete_package(
     db: AsyncSession = Depends(get_db),
 ):
     result = await db.execute(
-        select(RechargePackage).where(RechargePackage.id == pkg_id)
+        select(RechargePackage).where(RechargePackage.id == pkg_id).limit(1)
     )
     pkg = result.scalar_one_or_none()
     if not pkg:
diff --git a/video-gen-api/app/dependencies.py b/video-gen-api/app/dependencies.py
index 54a28b84..00a8eb2f 100644
--- a/video-gen-api/app/dependencies.py
+++ b/video-gen-api/app/dependencies.py
@@ -46,7 +46,7 @@ async def get_current_user(
             detail="无效的凭证",
         )
 
-    result = await db.execute(select(User).where(User.id == user_id))
+    result = await db.execute(select(User).where(User.id == user_id).limit(1))
     user = result.scalar_one_or_none()
     if not user or not user.is_active:
         raise HTTPException(
diff --git a/video-gen-api/app/main.py b/video-gen-api/app/main.py
index 198c14e0..1ceeb94a 100644
--- a/video-gen-api/app/main.py
+++ b/video-gen-api/app/main.py
@@ -77,7 +77,7 @@ async def _seed_data():
             db.add(admin_user)
 
         # Seed demo user
-        result = await db.execute(select(User).where(User.username == "demo"))
+        result = await db.execute(select(User).where(User.username == "demo").limit(1))
         demo = result.scalar_one_or_none()
         if not demo:
             demo_user = User(
@@ -114,7 +114,7 @@ async def _seed_data():
         ]
         for key, value, desc in configs:
             existing = await db.execute(
-                select(SystemConfig).where(SystemConfig.key == key)
+                select(SystemConfig).where(SystemConfig.key == key).limit(1)
             )
             if not existing.scalar_one_or_none():
                 db.add(
@@ -290,7 +290,7 @@ async def _seed_data():
         ]
         for path, label, icon, order, target in default_menus:
             existing = await db.execute(
-                select(MenuConfig).where(MenuConfig.path == path)
+                select(MenuConfig).where(MenuConfig.path == path).limit(1)
             )
             if not existing.scalar_one_or_none():
                 db.add(
@@ -320,6 +320,7 @@ async def _seed_data():
                     MenuConfig.menu_type == "group",
                     MenuConfig.menu_target == "admin",
                 )
+                .limit(1)
             )
             group = existing.scalar_one_or_none()
             if not group:
@@ -364,6 +365,7 @@ async def _seed_data():
                     MenuConfig.path == path,
                     MenuConfig.menu_target == "admin",
                 )
+                .limit(1)
             )
             if not existing.scalar_one_or_none():
                 db.add(
@@ -391,7 +393,7 @@ async def _seed_data():
         ]
         for name, credits, price, bonus, desc, ptype, order in default_packages:
             existing = await db.execute(
-                select(RechargePackage).where(RechargePackage.name == name)
+                select(RechargePackage).where(RechargePackage.name == name).limit(1)
             )
             if not existing.scalar_one_or_none():
                 db.add(
@@ -418,7 +420,7 @@ async def _seed_data():
         ]
         for key, label, icon, desc, order in default_industries:
             existing = await db.execute(
-                select(IndustryConfig).where(IndustryConfig.key == key)
+                select(IndustryConfig).where(IndustryConfig.key == key).limit(1)
             )
             if not existing.scalar_one_or_none():
                 db.add(
@@ -571,7 +573,7 @@ def create_app() -> FastAPI:
         # Update system config
         async with async_session() as db:
             result = await db.execute(
-                select(SystemConfig).where(SystemConfig.key == config_key)
+                select(SystemConfig).where(SystemConfig.key == config_key).limit(1)
             )
             config = result.scalar_one_or_none()
             if config:
diff --git a/video-gen-api/app/services/auth.py b/video-gen-api/app/services/auth.py
index 9407aeb8..9f7d0b0b 100644
--- a/video-gen-api/app/services/auth.py
+++ b/video-gen-api/app/services/auth.py
@@ -38,11 +38,11 @@ def decode_access_token(token: str) -> str | None:
 async def authenticate_user(
     db: AsyncSession, username: str, password: str
 ) -> User | None:
-    result = await db.execute(select(User).where(User.username == username))
+    result = await db.execute(select(User).where(User.username == username).limit(1))
     user = result.scalar_one_or_none()
     if not user:
         # Try phone number lookup for frontend users
-        result = await db.execute(select(User).where(User.phone == username))
+        result = await db.execute(select(User).where(User.phone == username).limit(1))
         user = result.scalar_one_or_none()
     if not user or not verify_password(password, user.hashed_password):
         return None
diff --git a/video-gen-api/app/services/credits.py b/video-gen-api/app/services/credits.py
index 99c8ee0a..eab2e46f 100644
--- a/video-gen-api/app/services/credits.py
+++ b/video-gen-api/app/services/credits.py
@@ -16,7 +16,7 @@ from app.utils.exceptions import InsufficientCreditsError
 async def calc_text_credits(db: AsyncSession, input_tokens: int, output_tokens: int) -> float:
     """Calculate text credits based on actual token usage and configurable rate."""
     result = await db.execute(
-        select(SystemConfig).where(SystemConfig.key == "text_credits_per_1000_tokens")
+        select(SystemConfig).where(SystemConfig.key == "text_credits_per_1000_tokens").limit(1)
     )
     config = result.scalar_one_or_none()
     rate = float(config.value) if config else 1.0
@@ -78,6 +78,7 @@ async def calc_video_credits(
             select(VideoEngine.id)
             .where(VideoEngine.is_active == True)
             .order_by(VideoEngine.priority.desc())
+            .limit(1)
         )
         engine_id = video_engines_result.scalar_one_or_none()
     ratio = await _get_credit_ratio(
@@ -122,6 +123,7 @@ async def calc_image_credits(
             select(ImageEngine.id)
             .where(ImageEngine.is_active == True)
             .order_by(ImageEngine.priority.desc())
+            .limit(1)
         )
         engine_id = image_engines_result.scalar_one_or_none()
     ratio = await _get_credit_ratio(
@@ -148,7 +150,7 @@ async def deduct_credits(
 ) -> User:
     """Atomically deduct credits from user. Raises InsufficientCreditsError."""
     result = await db.execute(
-        select(User).where(User.id == user_id)
+        select(User).where(User.id == user_id).limit(1)
     )
     user = result.scalar_one_or_none()
     if not user or user.credits < amount:
@@ -178,7 +180,7 @@ async def add_credits(
 ) -> User:
     """Add credits to user."""
     result = await db.execute(
-        select(User).where(User.id == user_id)
+        select(User).where(User.id == user_id).limit(1)
     )
     user = result.scalar_one_or_none()
     if not user:
diff --git a/video-gen-api/app/services/generation_ai_service.py b/video-gen-api/app/services/generation_ai_service.py
index a4edcd8b..3ceaed5a 100644
--- a/video-gen-api/app/services/generation_ai_service.py
+++ b/video-gen-api/app/services/generation_ai_service.py
@@ -78,7 +78,9 @@ async def _get_video_engine(db: AsyncSession, engine_id: str | None) -> VideoEng
     if engine_id:
         query = query.where(VideoEngine.id == engine_id)
     else:
-        query = query.order_by(VideoEngine.priority.desc()).limit(1)
+        query = query.order_by(VideoEngine.priority.desc())
+
+    query = query.limit(1)
     result = await db.execute(query)
     engine = result.scalar_one_or_none()
     if not engine:
diff --git a/video-gen-api/app/services/generation_billing_service.py b/video-gen-api/app/services/generation_billing_service.py
index eb9865c3..30c33938 100644
--- a/video-gen-api/app/services/generation_billing_service.py
+++ b/video-gen-api/app/services/generation_billing_service.py
@@ -145,7 +145,7 @@ async def deduct_credits_locked_once(
     if amount <= 0:
         return BillingItem(charge_key=charge_key, amount=0.0, charged=False, skipped_reason="amount_lte_zero")
 
-    result = await db.execute(select(User).where(User.id == user_id).with_for_update())
+    result = await db.execute(select(User).where(User.id == user_id).with_for_update().limit(1))
     user = result.scalar_one_or_none()
     if not user:
         raise ValueError("User not found")
diff --git a/video-gen-api/app/services/generation_provider_service.py b/video-gen-api/app/services/generation_provider_service.py
index 9dd53fb1..e221c0ba 100644
--- a/video-gen-api/app/services/generation_provider_service.py
+++ b/video-gen-api/app/services/generation_provider_service.py
@@ -35,9 +35,9 @@ async def get_runtime_engine(db: AsyncSession, task: ChatGenerationTask) -> Any:
     if not task.engine_id:
         raise ValueError("缺少 engine_id")
     if task.gen_type == "image":
-        result = await db.execute(select(ImageEngine).where(ImageEngine.id == task.engine_id))
+        result = await db.execute(select(ImageEngine).where(ImageEngine.id == task.engine_id).limit(1))
     else:
-        result = await db.execute(select(VideoEngine).where(VideoEngine.id == task.engine_id))
+        result = await db.execute(select(VideoEngine).where(VideoEngine.id == task.engine_id).limit(1))
     engine = result.scalar_one_or_none()
     if not engine:
         raise ValueError("引擎不存在或已删除")
diff --git a/video-gen-api/app/services/llm.py b/video-gen-api/app/services/llm.py
index 0a2a67d6..79878493 100644
--- a/video-gen-api/app/services/llm.py
+++ b/video-gen-api/app/services/llm.py
@@ -180,7 +180,7 @@ async def _call_openai_compatible(
     if industry_key and db is not None:
         from app.models.industry_config import IndustryConfig
         result = await db.execute(
-            select(IndustryConfig).where(IndustryConfig.key == industry_key)
+            select(IndustryConfig).where(IndustryConfig.key == industry_key).limit(1)
         )
         ind = result.scalar_one_or_none()
         if ind and ind.skills:
diff --git a/video-gen-api/app/services/notification.py b/video-gen-api/app/services/notification.py
index 8f786cb9..7dfb16d4 100644
--- a/video-gen-api/app/services/notification.py
+++ b/video-gen-api/app/services/notification.py
@@ -132,7 +132,7 @@ async def get_notifications(
 async def mark_read(db: AsyncSession, notification_id: str, user_id: str) -> None:
     """Mark a notification as read for a specific user."""
     result = await db.execute(
-        select(Notification).where(Notification.id == notification_id)
+        select(Notification).where(Notification.id == notification_id).limit(1)
     )
     notif = result.scalar_one_or_none()
     if not notif:
@@ -150,6 +150,7 @@ async def mark_read(db: AsyncSession, notification_id: str, user_id: str) -> Non
                 NotificationRead.notification_id == notification_id,
                 NotificationRead.user_id == user_id,
             )
+            .limit(1)
         )
         if not existing.scalar_one_or_none():
             db.add(NotificationRead(
diff --git a/video-gen-api/app/services/payment.py b/video-gen-api/app/services/payment.py
index fc989429..ed0e8946 100644
--- a/video-gen-api/app/services/payment.py
+++ b/video-gen-api/app/services/payment.py
@@ -104,7 +104,7 @@ async def process_payment_success(db: AsyncSession, order_id: str):
     from sqlalchemy import select
 
     result = await db.execute(
-        select(PaymentOrder).where(PaymentOrder.id == order_id)
+        select(PaymentOrder).where(PaymentOrder.id == order_id).limit(1)
     )
     order = result.scalar_one_or_none()
     if not order or order.status != "pending":
diff --git a/video-gen-api/app/services/resource_accounting_service.py b/video-gen-api/app/services/resource_accounting_service.py
index 350dd4d4..b6bc20ac 100644
--- a/video-gen-api/app/services/resource_accounting_service.py
+++ b/video-gen-api/app/services/resource_accounting_service.py
@@ -84,6 +84,7 @@ async def _get_or_create_month_stat(
             UserResourceMonthStat.user_id == user_id,
             UserResourceMonthStat.stat_month == stat_month,
         )
+        .limit(1)
     )
     stat = result.scalar_one_or_none()
     if stat:
@@ -104,7 +105,7 @@ async def _get_or_create_total_stat(
     user_id: str,
 ) -> UserResourceTotalStat:
     result = await db.execute(
-        select(UserResourceTotalStat).where(UserResourceTotalStat.user_id == user_id)
+        select(UserResourceTotalStat).where(UserResourceTotalStat.user_id == user_id).limit(1)
     )
     stat = result.scalar_one_or_none()
     if stat:
diff --git a/video-gen-api/app/services/video_queue.py b/video-gen-api/app/services/video_queue.py
index 8d4dca26..2578564c 100644
--- a/video-gen-api/app/services/video_queue.py
+++ b/video-gen-api/app/services/video_queue.py
@@ -76,6 +76,7 @@ class TaskQueue:
                     GenerationRecord.id == record_id,
                     GenerationRecord.deleted_at.is_(None),
                 )
+                .limit(1)
             )
             record = result.scalar_one_or_none()
             if not record or record.status != "generating":
diff --git a/video-gen-api/app/services/video_url.py b/video-gen-api/app/services/video_url.py
index a8358a51..fef91831 100644
--- a/video-gen-api/app/services/video_url.py
+++ b/video-gen-api/app/services/video_url.py
@@ -29,5 +29,6 @@ async def get_video_stream_url(db: AsyncSession, record_id: str) -> str | None:
             GenerationRecord.id == record_id,
             GenerationRecord.deleted_at.is_(None),
         )
+        .limit(1)
     )
     return result.scalar_one_or_none()
diff --git a/video-gen-api/app/tasks/generation_create_tasks.py b/video-gen-api/app/tasks/generation_create_tasks.py
index 93655896..dd5262b9 100644
--- a/video-gen-api/app/tasks/generation_create_tasks.py
+++ b/video-gen-api/app/tasks/generation_create_tasks.py
@@ -109,7 +109,7 @@ async def _run(task_id: str):
         result = await db.execute(select(ChatGenerationTask).where(
             ChatGenerationTask.id == task_id,
             ChatGenerationTask.deleted_at.is_(None),
-        ))
+        ).limit(1))
         task = result.scalar_one_or_none()
 
         if not task or task.generation_mode != "chatapi_async":
@@ -236,7 +236,7 @@ async def _run(task_id: str):
             result = await db.execute(select(ChatGenerationTask).where(
                 ChatGenerationTask.id == task_id,
                 ChatGenerationTask.deleted_at.is_(None),
-            ))
+            ).limit(1))
             task = result.scalar_one_or_none()
 
             if task:
diff --git a/video-gen-api/app/tasks/generation_download_tasks.py b/video-gen-api/app/tasks/generation_download_tasks.py
index e459a966..993e22b2 100644
--- a/video-gen-api/app/tasks/generation_download_tasks.py
+++ b/video-gen-api/app/tasks/generation_download_tasks.py
@@ -61,7 +61,7 @@ async def _reload_task(db, task_id: str) -> ChatGenerationTask | None:
         select(ChatGenerationTask).where(
             ChatGenerationTask.id == task_id,
             ChatGenerationTask.deleted_at.is_(None),
-        )
+        ).limit(1)
     )
     return result.scalar_one_or_none()
 
@@ -72,7 +72,7 @@ async def _run(task_id: str):
             select(ChatGenerationTask).where(
                 ChatGenerationTask.id == task_id,
                 ChatGenerationTask.deleted_at.is_(None),
-            )
+            ).limit(1)
         )
         task = result.scalar_one_or_none()
         if not task or task.generation_mode != "chatapi_async":
diff --git a/video-gen-api/app/tasks/generation_poll_tasks.py b/video-gen-api/app/tasks/generation_poll_tasks.py
index 7ba4cc0e..5bf04f36 100644
--- a/video-gen-api/app/tasks/generation_poll_tasks.py
+++ b/video-gen-api/app/tasks/generation_poll_tasks.py
@@ -41,7 +41,7 @@ async def _reload_task(db, task_id: str) -> ChatGenerationTask | None:
         select(ChatGenerationTask).where(
             ChatGenerationTask.id == task_id,
             ChatGenerationTask.deleted_at.is_(None),
-        )
+        ).limit(1)
     )
     return result.scalar_one_or_none()
 
@@ -51,7 +51,7 @@ async def _run(task_id: str):
         result = await db.execute(select(ChatGenerationTask).where(
             ChatGenerationTask.id == task_id,
             ChatGenerationTask.deleted_at.is_(None),
-        ))
+        ).limit(1))
         task = result.scalar_one_or_none()
         if not task or task.generation_mode != "chatapi_async":
             return