Refactor: replace count() > 0 check with exists() (#24583)

Co-authored-by: Yongtao Huang <99629139+hyongtao-db@users.noreply.github.com>
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>

api/services/dataset_service.py

@@ -9,7 +9,7 @@ from collections import Counter
 from typing import Any, Literal, Optional
 
 from flask_login import current_user
-from sqlalchemy import func, select
+from sqlalchemy import exists, func, select
 from sqlalchemy.orm import Session
 from werkzeug.exceptions import NotFound
 
@@ -655,10 +655,8 @@ class DatasetService:
 
     @staticmethod
     def dataset_use_check(dataset_id) -> bool:
-        count = db.session.query(AppDatasetJoin).filter_by(dataset_id=dataset_id).count()
-        if count > 0:
-            return True
-        return False
+        stmt = select(exists().where(AppDatasetJoin.dataset_id == dataset_id))
+        return db.session.execute(stmt).scalar_one()
 
     @staticmethod
     def check_dataset_permission(dataset, user):

api/services/tools/builtin_tools_manage_service.py

@@ -5,6 +5,7 @@ from collections.abc import Mapping
 from pathlib import Path
 from typing import Any, Optional
 
+from sqlalchemy import exists, select
 from sqlalchemy.orm import Session
 
 from configs import dify_config
@@ -190,11 +191,14 @@ class BuiltinToolManageService:
                 # update name if provided
                 if name and name != db_provider.name:
                     # check if the name is already used
-                    if (
-                        session.query(BuiltinToolProvider)
-                        .filter_by(tenant_id=tenant_id, provider=provider, name=name)
-                        .count()
-                        > 0
+                    if session.scalar(
+                        select(
+                            exists().where(
+                                BuiltinToolProvider.tenant_id == tenant_id,
+                                BuiltinToolProvider.provider == provider,
+                                BuiltinToolProvider.name == name,
+                            )
+                        )
                     ):
                         raise ValueError(f"the credential name '{name}' is already used")
 
@@ -246,11 +250,14 @@ class BuiltinToolManageService:
                         )
                     else:
                         # check if the name is already used
-                        if (
-                            session.query(BuiltinToolProvider)
-                            .filter_by(tenant_id=tenant_id, provider=provider, name=name)
-                            .count()
-                            > 0
+                        if session.scalar(
+                            select(
+                                exists().where(
+                                    BuiltinToolProvider.tenant_id == tenant_id,
+                                    BuiltinToolProvider.provider == provider,
+                                    BuiltinToolProvider.name == name,
+                                )
+                            )
                         ):
                             raise ValueError(f"the credential name '{name}' is already used")
 

api/services/workflow_service.py

@@ -5,7 +5,7 @@ from collections.abc import Callable, Generator, Mapping, Sequence
 from typing import Any, Optional, cast
 from uuid import uuid4
 
-from sqlalchemy import select
+from sqlalchemy import exists, select
 from sqlalchemy.orm import Session, sessionmaker
 
 from core.app.app_config.entities import VariableEntityType
@@ -87,15 +87,14 @@ class WorkflowService:
         )
 
     def is_workflow_exist(self, app_model: App) -> bool:
-        return (
-            db.session.query(Workflow)
-            .where(
+        stmt = select(
+            exists().where(
                 Workflow.tenant_id == app_model.tenant_id,
                 Workflow.app_id == app_model.id,
                 Workflow.version == Workflow.VERSION_DRAFT,
             )
-            .count()
-        ) > 0
+        )
+        return db.session.execute(stmt).scalar_one()
 
     def get_draft_workflow(self, app_model: App) -> Optional[Workflow]:
         """