diff --git a/api/tests/unit_tests/commands/test_legacy_model_type_migration.py b/api/tests/unit_tests/commands/test_legacy_model_type_migration.py
index e14c8ed3243..9eb73b82516 100644
--- a/api/tests/unit_tests/commands/test_legacy_model_type_migration.py
+++ b/api/tests/unit_tests/commands/test_legacy_model_type_migration.py
@@ -32,15 +32,6 @@ from tests.helpers.legacy_model_type_migration import (
 )
 
 
-@pytest.fixture
-def sqlite_engine(tmp_path: Path) -> sa.Engine:
-    engine = sa.create_engine(f"sqlite:///{tmp_path / 'legacy_model_type_migration.sqlite'}")
-    try:
-        yield engine
-    finally:
-        engine.dispose()
-
-
 @pytest.fixture
 def dirty_fixture(sqlite_engine: sa.Engine):
     return seed_legacy_model_type_dirty_data(sqlite_engine)
diff --git a/api/tests/unit_tests/conftest.py b/api/tests/unit_tests/conftest.py
index 7174530e976..d95e5e8501d 100644
--- a/api/tests/unit_tests/conftest.py
+++ b/api/tests/unit_tests/conftest.py
@@ -1,9 +1,12 @@
 import os
+from collections.abc import Iterator
 from unittest.mock import MagicMock, patch
 
 import pytest
 from flask import Flask
 from sqlalchemy import create_engine
+from sqlalchemy.engine import Engine
+from sqlalchemy.orm import Session, sessionmaker
 
 # Getting the absolute path of the current file's directory
 ABS_PATH = os.path.dirname(os.path.abspath(__file__))
@@ -34,6 +37,7 @@ os.environ.setdefault("STORAGE_TYPE", "opendal")
 
 from core.db.session_factory import configure_session_factory, session_factory
 from extensions import ext_redis
+from models.base import TypeBase
 
 
 def _patch_redis_clients_on_loaded_modules():
@@ -113,6 +117,29 @@ def _unit_test_engine():
     engine.dispose()
 
 
+@pytest.fixture
+def sqlite_engine() -> Iterator[Engine]:
+    """Create an isolated in-memory SQLite engine for tests that need a disposable database."""
+
+    engine = create_engine("sqlite:///:memory:")
+    try:
+        yield engine
+    finally:
+        engine.dispose()
+
+
+@pytest.fixture
+def sqlite_session(request: pytest.FixtureRequest, sqlite_engine: Engine) -> Iterator[Session]:
+    """Yield a SQLite session after creating the model tables passed through ``request.param``."""
+
+    models: tuple[type[TypeBase], ...] = request.param
+    tables = [model.metadata.tables[model.__tablename__] for model in models]
+    TypeBase.metadata.create_all(sqlite_engine, tables=tables)
+    session_factory = sessionmaker(bind=sqlite_engine, expire_on_commit=False)
+    with session_factory() as session:
+        yield session
+
+
 @pytest.fixture(autouse=True)
 def _configure_session_factory(_unit_test_engine):
     try:
diff --git a/api/tests/unit_tests/services/test_account_service.py b/api/tests/unit_tests/services/test_account_service.py
index 498e295447e..233191ca0b7 100644
--- a/api/tests/unit_tests/services/test_account_service.py
+++ b/api/tests/unit_tests/services/test_account_service.py
@@ -1,16 +1,13 @@
 import json
-from collections.abc import Iterator
 from datetime import datetime, timedelta
 from types import SimpleNamespace
 from unittest.mock import MagicMock, patch
 
 import pytest
-from sqlalchemy import create_engine
 from sqlalchemy.orm import Session
 
 from configs import dify_config
 from models.account import Account, AccountStatus, TenantAccountRole, TenantStatus
-from models.base import TypeBase
 from services.account_service import AccountService, RegisterService, TenantService
 from services.errors.account import (
     AccountAlreadyInTenantError,
@@ -22,16 +19,6 @@ from services.errors.account import (
 )
 
 
-@pytest.fixture
-def sqlite_session(request: pytest.FixtureRequest) -> Iterator[Session]:
-    models: tuple[type[TypeBase], ...] = request.param
-    engine = create_engine("sqlite:///:memory:")
-    tables = [model.metadata.tables[model.__tablename__] for model in models]
-    Account.metadata.create_all(engine, tables=tables)
-    with Session(engine, expire_on_commit=False) as session:
-        yield session
-
-
 class TestAccountAssociatedDataFactory:
     """Factory class for creating test data and mock objects for account service tests."""