diff --git a/app/core/database.py b/app/core/database.py
index 40901120..2d96c357 100644
--- a/app/core/database.py
+++ b/app/core/database.py
@@ -1,5 +1,5 @@
 from sqlalchemy import create_engine
-from sqlalchemy.ext.declarative import declarative_base
+from sqlalchemy.orm import declarative_base
 from sqlalchemy.orm import sessionmaker, Session
 from .config import settings
 
diff --git a/models/api_models.py b/models/api_models.py
index c1ba1f97..7895953b 100644
--- a/models/api_models.py
+++ b/models/api_models.py
@@ -1,5 +1,5 @@
-# models/api_models.py - Updated with Marketplace Support
-from pydantic import BaseModel, Field, field_validator, EmailStr
+# models/api_models.py - Updated with Marketplace Support and Pydantic v2
+from pydantic import BaseModel, Field, field_validator, EmailStr, ConfigDict
 from typing import Optional, List
 from datetime import datetime
 
@@ -36,6 +36,8 @@ class UserLogin(BaseModel):
 
 
 class UserResponse(BaseModel):
+    model_config = ConfigDict(from_attributes=True)
+
     id: int
     email: str
     username: str
@@ -45,8 +47,6 @@ class UserResponse(BaseModel):
     created_at: datetime
     updated_at: datetime
 
-    model_config = {"from_attributes": True}
-
 
 class LoginResponse(BaseModel):
     access_token: str
@@ -98,6 +98,8 @@ class ShopUpdate(BaseModel):
 
 
 class ShopResponse(BaseModel):
+    model_config = ConfigDict(from_attributes=True)
+
     id: int
     shop_code: str
     shop_name: str
@@ -113,9 +115,6 @@ class ShopResponse(BaseModel):
     created_at: datetime
     updated_at: datetime
 
-    class Config:
-        from_attributes = True
-
 
 class ShopListResponse(BaseModel):
     shops: List[ShopResponse]
@@ -185,12 +184,12 @@ class ProductUpdate(ProductBase):
 
 
 class ProductResponse(ProductBase):
+    model_config = ConfigDict(from_attributes=True)
+
     id: int
     created_at: datetime
     updated_at: datetime
 
-    model_config = {"from_attributes": True}
-
 
 # NEW: Shop Product models
 class ShopProductCreate(BaseModel):
@@ -207,6 +206,8 @@ class ShopProductCreate(BaseModel):
 
 
 class ShopProductResponse(BaseModel):
+    model_config = ConfigDict(from_attributes=True)
+
     id: int
     shop_id: int
     product: ProductResponse
@@ -223,9 +224,6 @@ class ShopProductResponse(BaseModel):
     created_at: datetime
     updated_at: datetime
 
-    class Config:
-        from_attributes = True
-
 
 # Stock Models
 class StockBase(BaseModel):
@@ -246,6 +244,8 @@ class StockUpdate(BaseModel):
 
 
 class StockResponse(BaseModel):
+    model_config = ConfigDict(from_attributes=True)
+
     id: int
     gtin: str
     location: str
@@ -253,8 +253,6 @@ class StockResponse(BaseModel):
     created_at: datetime
     updated_at: datetime
 
-    model_config = {"from_attributes": True}
-
 
 class StockLocationResponse(BaseModel):
     location: str
diff --git a/models/database_models.py b/models/database_models.py
index b1857df2..b93affb8 100644
--- a/models/database_models.py
+++ b/models/database_models.py
@@ -1,10 +1,10 @@
 # models/database_models.py - Updated with Marketplace Support
 from sqlalchemy import Column, Integer, String, Float, DateTime, Boolean, Text, ForeignKey, UniqueConstraint, Index
-from sqlalchemy.ext.declarative import declarative_base
 from sqlalchemy.orm import relationship
 from datetime import datetime
 
-Base = declarative_base()
+# Import Base from the central database module instead of creating a new one
+from app.core.database import Base
 
 
 class User(Base):
diff --git a/tests/conftest.py b/tests/conftest.py
index 6766b091..f01efb16 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -9,7 +9,8 @@ from sqlalchemy.pool import StaticPool
 
 from main import app
 from app.core.database import get_db, Base
-from models.database_models import User, Product, Stock, Shop
+# Import all models to ensure they're registered with Base metadata
+from models.database_models import User, Product, Stock, Shop, MarketplaceImportJob, ShopProduct
 from middleware.auth import AuthManager
 
 # Use in-memory SQLite database for tests
@@ -35,38 +36,41 @@ def testing_session_local(engine):
 
 @pytest.fixture(scope="function")
 def db(engine, testing_session_local):
-    """Create a fresh database for each test"""
+    """Create a database session for direct database operations"""
     # Create all tables
     Base.metadata.create_all(bind=engine)
 
     # Create session
-    db = testing_session_local()
+    db_session = testing_session_local()
 
-    # Override the dependency
+    try:
+        yield db_session
+    finally:
+        db_session.rollback()
+        db_session.close()
+        # Tables will be dropped by the client fixture
+
+
+@pytest.fixture(scope="function")
+def client(db):  # Now client depends on db
+    """Create a test client with database dependency override"""
+
+    # Override the dependency to use our test database
     def override_get_db():
         try:
             yield db
         finally:
-            pass  # Don't close here, we'll close in cleanup
+            pass  # Don't close here, the db fixture handles it
 
     app.dependency_overrides[get_db] = override_get_db
 
     try:
-        yield db
+        client = TestClient(app)
+        yield client
     finally:
-        db.rollback()  # Rollback any uncommitted changes
-        db.close()
         # Clean up the dependency override
         if get_db in app.dependency_overrides:
             del app.dependency_overrides[get_db]
-        # Drop all tables for next test
-        Base.metadata.drop_all(bind=engine)
-
-
-@pytest.fixture(scope="function")
-def client(db):
-    """Create a test client with database dependency override"""
-    return TestClient(app)
 
 
 @pytest.fixture(scope="session")
@@ -174,10 +178,11 @@ def test_shop(db, test_user):
 def test_stock(db, test_product, test_shop):
     """Create test stock entry"""
     stock = Stock(
-        product_id=test_product.product_id,
-        shop_code=test_shop.shop_code,
+        gtin=test_product.gtin,  # Fixed: use gtin instead of product_id
+        location=test_shop.shop_code,  # Fixed: use location instead of shop_code
         quantity=10,
-        reserved_quantity=0
+        reserved_quantity=0,
+        shop_id=test_shop.id  # Add shop_id reference
     )
     db.add(stock)
     db.commit()
diff --git a/tests/test_auth.py b/tests/test_auth.py
index ffa2cd22..75186165 100644
--- a/tests/test_auth.py
+++ b/tests/test_auth.py
@@ -66,7 +66,7 @@ class TestAuthenticationAPI:
         assert response.status_code == 401
         assert "Incorrect username or password" in response.json()["detail"]
 
-    def test_login_nonexistent_user(self, client):
+    def test_login_nonexistent_user(self, client, db):  # Added db fixture
         """Test login with nonexistent user"""
         response = client.post("/api/v1/auth/login", json={
             "username": "nonexistent",
@@ -116,4 +116,3 @@ class TestAuthManager:
         assert token_data["token_type"] == "bearer"
         assert "expires_in" in token_data
         assert isinstance(token_data["expires_in"], int)
-