diff --git a/README.md b/README.md
index f4da31a3c3db23c6a22bd88a23461d1db605c580..fa2ea3c728019256a800bff1696aa1259404774d 100644
--- a/README.md
+++ b/README.md
@@ -146,7 +146,7 @@ curl --location 'localhost:8080/bankaccounts' \
 To increase or decrease the Accountbalance, this Function can be used.
 The Bankaccount will be detected by the username in the Token-String.
 ```
-curl --location --request PUT 'localhost:8080/bankaccounts' \
+curl --location --request PUT 'localhost:8080/bankaccounts/transfer' \
 --header 'Content-Type: application/json' \
 --header 'Authorization: Bearer INSERT_TOKEN_HERE' \
 --data '{
@@ -178,12 +178,15 @@ curl --location 'localhost:8080/shoppingcart/Product/1' \
 
 #### PAY SHOPPINGCART (TOKEN REQUIRED)
 With this Function, all Products will be buyed. If the Balance is lesser than the Totalprice, the Payment process will be canceled.
-If the Payment process is successfull, the Shoppingcart will be tranformed into the default version.
+If the Payment process is successfull, the Shoppingcart will be deleted.
 The user will also be detected with the Token-String.
 ```
 curl --location --request POST 'localhost:8080/shoppingcart/pay' \
 --header 'Authorization: Bearer INSERT_TOKEN_HERE'
 ```
 
+### Testing the API-Calls
+Because of the frequent specification of the JWT token, API calls with CURL can be bothersome. Therefore a postman collection can be imported with the file `go-mazon.postman_collection`. Import this to your Postman for more comfortable tests.
+
 ## Troubleshooting
 If Docker doesn't detect a specific file, check if in VS-Code all Docker-related files has LF (Line Feed) and not CRLF (Carriage Return).
\ No newline at end of file
diff --git a/go-mazon.postman_collection.json b/go-mazon.postman_collection.json
new file mode 100644
index 0000000000000000000000000000000000000000..998a104014349e3228d18aeddd0833e20d61d09b
--- /dev/null
+++ b/go-mazon.postman_collection.json
@@ -0,0 +1,484 @@
+{
+	"info": {
+		"_postman_id": "296ee443-995b-40b8-8d80-e20b0cce75e7",
+		"name": "go-mazon",
+		"schema": "https://schema.getpostman.com/json/collection/v2.1.0/collection.json",
+		"_exporter_id": "27954253"
+	},
+	"item": [
+		{
+			"name": "Product",
+			"item": [
+				{
+					"name": "New Product (Admin only)",
+					"request": {
+						"auth": {
+							"type": "bearer",
+							"bearer": [
+								{
+									"key": "token",
+									"value": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJleHAiOjE2ODkwNTU0NTEsImlzQWRtaW4iOnRydWUsInVzZXJuYW1lIjoiYWRtaW4ifQ.m_Ftfnb5ZHGV6fOCgY6-uIz19z1g-Ln976VdtfXHjJM",
+									"type": "string"
+								}
+							]
+						},
+						"method": "POST",
+						"header": [],
+						"body": {
+							"mode": "raw",
+							"raw": "{\r\n    \"name\": \"IPhone\",\r\n    \"description\": \"Smartphone\",\r\n    \"price\": 1200.00\r\n}",
+							"options": {
+								"raw": {
+									"language": "json"
+								}
+							}
+						},
+						"url": {
+							"raw": "localhost:8080/products",
+							"host": [
+								"localhost"
+							],
+							"port": "8080",
+							"path": [
+								"products"
+							]
+						}
+					},
+					"response": []
+				},
+				{
+					"name": "Get Product",
+					"request": {
+						"method": "GET",
+						"header": [],
+						"url": {
+							"raw": "localhost:8080/products",
+							"host": [
+								"localhost"
+							],
+							"port": "8080",
+							"path": [
+								"products"
+							]
+						}
+					},
+					"response": []
+				},
+				{
+					"name": "Get Single Product",
+					"request": {
+						"method": "GET",
+						"header": [],
+						"url": {
+							"raw": "localhost:8080/products/1",
+							"host": [
+								"localhost"
+							],
+							"port": "8080",
+							"path": [
+								"products",
+								"1"
+							]
+						}
+					},
+					"response": []
+				},
+				{
+					"name": "Update Product (Admin only)",
+					"request": {
+						"auth": {
+							"type": "bearer",
+							"bearer": [
+								{
+									"key": "token",
+									"value": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJleHAiOjE2ODkwNTU0NTEsImlzQWRtaW4iOnRydWUsInVzZXJuYW1lIjoiYWRtaW4ifQ.m_Ftfnb5ZHGV6fOCgY6-uIz19z1g-Ln976VdtfXHjJM",
+									"type": "string"
+								}
+							]
+						},
+						"method": "PUT",
+						"header": [],
+						"body": {
+							"mode": "raw",
+							"raw": "{\r\n    \"name\": \"AirPodsv2\",\r\n    \"description\": \"bessere Akkuleistung\",\r\n    \"price\": 150.00\r\n}",
+							"options": {
+								"raw": {
+									"language": "json"
+								}
+							}
+						},
+						"url": {
+							"raw": "localhost:8080/products/1",
+							"host": [
+								"localhost"
+							],
+							"port": "8080",
+							"path": [
+								"products",
+								"1"
+							]
+						}
+					},
+					"response": []
+				},
+				{
+					"name": "Delete Product (Admin only)",
+					"request": {
+						"auth": {
+							"type": "bearer",
+							"bearer": [
+								{
+									"key": "token",
+									"value": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJleHAiOjE2ODkwNTU0NTEsImlzQWRtaW4iOnRydWUsInVzZXJuYW1lIjoiYWRtaW4ifQ.m_Ftfnb5ZHGV6fOCgY6-uIz19z1g-Ln976VdtfXHjJM",
+									"type": "string"
+								}
+							]
+						},
+						"method": "DELETE",
+						"header": [],
+						"url": {
+							"raw": "localhost:8080/products/1",
+							"host": [
+								"localhost"
+							],
+							"port": "8080",
+							"path": [
+								"products",
+								"1"
+							]
+						}
+					},
+					"response": []
+				}
+			]
+		},
+		{
+			"name": "Shopping Cart",
+			"item": [
+				{
+					"name": "Create Shopping Cart",
+					"request": {
+						"auth": {
+							"type": "bearer",
+							"bearer": [
+								{
+									"key": "token",
+									"value": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJleHAiOjE2ODkwNTU0MjgsImlzQWRtaW4iOmZhbHNlLCJ1c2VybmFtZSI6Imt1bmRlIn0.xhUq428zDHSbeVdENzo99Gy_FZ3KTdDArcHKcmHUUjA",
+									"type": "string"
+								}
+							]
+						},
+						"method": "POST",
+						"header": [],
+						"url": {
+							"raw": "localhost:8080/shoppingcart",
+							"host": [
+								"localhost"
+							],
+							"port": "8080",
+							"path": [
+								"shoppingcart"
+							]
+						}
+					},
+					"response": []
+				},
+				{
+					"name": "Add Product to Shopping Cart",
+					"request": {
+						"auth": {
+							"type": "bearer",
+							"bearer": [
+								{
+									"key": "token",
+									"value": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJleHAiOjE2ODkwNTY4MTQsImlzQWRtaW4iOnRydWUsInVzZXJuYW1lIjoiYWRtaW4ifQ.hk1ZetULOkGLkYcPPVGidp5Y9w-Rzsxa-ja0WWC-CSA",
+									"type": "string"
+								}
+							]
+						},
+						"method": "POST",
+						"header": [],
+						"body": {
+							"mode": "raw",
+							"raw": "{\r\n  \"amount\": 1\r\n}",
+							"options": {
+								"raw": {
+									"language": "json"
+								}
+							}
+						},
+						"url": {
+							"raw": "localhost:8080/shoppingcart/product/1",
+							"host": [
+								"localhost"
+							],
+							"port": "8080",
+							"path": [
+								"shoppingcart",
+								"product",
+								"1"
+							]
+						}
+					},
+					"response": []
+				},
+				{
+					"name": "Pay",
+					"request": {
+						"auth": {
+							"type": "bearer",
+							"bearer": [
+								{
+									"key": "token",
+									"value": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJleHAiOjE2ODkwNTY4MTQsImlzQWRtaW4iOnRydWUsInVzZXJuYW1lIjoiYWRtaW4ifQ.hk1ZetULOkGLkYcPPVGidp5Y9w-Rzsxa-ja0WWC-CSA",
+									"type": "string"
+								}
+							]
+						},
+						"method": "POST",
+						"header": [],
+						"url": {
+							"raw": "localhost:8080/shoppingcart/pay",
+							"host": [
+								"localhost"
+							],
+							"port": "8080",
+							"path": [
+								"shoppingcart",
+								"pay"
+							]
+						}
+					},
+					"response": []
+				}
+			]
+		},
+		{
+			"name": "Bank",
+			"item": [
+				{
+					"name": "Add Bankacc",
+					"request": {
+						"auth": {
+							"type": "bearer",
+							"bearer": [
+								{
+									"key": "token",
+									"value": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJleHAiOjE2ODkwNTY4MTQsImlzQWRtaW4iOnRydWUsInVzZXJuYW1lIjoiYWRtaW4ifQ.hk1ZetULOkGLkYcPPVGidp5Y9w-Rzsxa-ja0WWC-CSA",
+									"type": "string"
+								}
+							]
+						},
+						"method": "POST",
+						"header": [],
+						"body": {
+							"mode": "raw",
+							"raw": "{\r\n    \"iban\": \"DE1234\",\r\n    \"bankName\": \"Sparkasse\",\r\n    \"balance\": -2000.00\r\n}",
+							"options": {
+								"raw": {
+									"language": "json"
+								}
+							}
+						},
+						"url": {
+							"raw": "localhost:8080/bankaccounts",
+							"host": [
+								"localhost"
+							],
+							"port": "8080",
+							"path": [
+								"bankaccounts"
+							]
+						}
+					},
+					"response": []
+				},
+				{
+					"name": "Transaction",
+					"request": {
+						"auth": {
+							"type": "bearer",
+							"bearer": [
+								{
+									"key": "token",
+									"value": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJleHAiOjE2ODkwMTk5NjYsImlzQWRtaW4iOnRydWUsInVzZXJuYW1lIjoia3VuZGUifQ.eLJ0Bv50HcZT5zpEoKgnSo4AeildgHH_ABSr0AXxzkM",
+									"type": "string"
+								}
+							]
+						},
+						"method": "PUT",
+						"header": [],
+						"body": {
+							"mode": "raw",
+							"raw": "{\r\n  \"amount\": 5000.0\r\n}",
+							"options": {
+								"raw": {
+									"language": "json"
+								}
+							}
+						},
+						"url": {
+							"raw": "localhost:8080/bankaccounts/transfer",
+							"host": [
+								"localhost"
+							],
+							"port": "8080",
+							"path": [
+								"bankaccounts",
+								"transfer"
+							]
+						}
+					},
+					"response": []
+				}
+			]
+		},
+		{
+			"name": "Rating",
+			"item": [
+				{
+					"name": "New Rating",
+					"request": {
+						"auth": {
+							"type": "bearer",
+							"bearer": [
+								{
+									"key": "token",
+									"value": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJleHAiOjE2ODkwNTU0MjgsImlzQWRtaW4iOmZhbHNlLCJ1c2VybmFtZSI6Imt1bmRlIn0.xhUq428zDHSbeVdENzo99Gy_FZ3KTdDArcHKcmHUUjA",
+									"type": "string"
+								}
+							]
+						},
+						"method": "POST",
+						"header": [],
+						"body": {
+							"mode": "raw",
+							"raw": "{\r\n    \"Content\": \"Fantastic Product!\",\r\n    \"Rating\": 0\r\n}",
+							"options": {
+								"raw": {
+									"language": "json"
+								}
+							}
+						},
+						"url": {
+							"raw": "localhost:8080/products/1/rating",
+							"host": [
+								"localhost"
+							],
+							"port": "8080",
+							"path": [
+								"products",
+								"1",
+								"rating"
+							]
+						}
+					},
+					"response": []
+				},
+				{
+					"name": "Delete Rating",
+					"request": {
+						"auth": {
+							"type": "bearer",
+							"bearer": [
+								{
+									"key": "token",
+									"value": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJleHAiOjE2ODkwNTU0NTEsImlzQWRtaW4iOnRydWUsInVzZXJuYW1lIjoiYWRtaW4ifQ.m_Ftfnb5ZHGV6fOCgY6-uIz19z1g-Ln976VdtfXHjJM",
+									"type": "string"
+								}
+							]
+						},
+						"method": "DELETE",
+						"header": [],
+						"url": {
+							"raw": "localhost:8080/ratings/3",
+							"host": [
+								"localhost"
+							],
+							"port": "8080",
+							"path": [
+								"ratings",
+								"3"
+							]
+						}
+					},
+					"response": []
+				},
+				{
+					"name": "Read Ratings",
+					"request": {
+						"auth": {
+							"type": "noauth"
+						},
+						"method": "GET",
+						"header": [],
+						"url": {
+							"raw": "localhost:8080/ratings",
+							"host": [
+								"localhost"
+							],
+							"port": "8080",
+							"path": [
+								"ratings"
+							]
+						}
+					},
+					"response": []
+				}
+			]
+		},
+		{
+			"name": "Token",
+			"item": [
+				{
+					"name": "Get JWT",
+					"protocolProfileBehavior": {
+						"disableBodyPruning": true
+					},
+					"request": {
+						"method": "GET",
+						"header": [],
+						"body": {
+							"mode": "raw",
+							"raw": "{\r\n    \"username\": \"admin\",\r\n    \"isAdmin\": true\r\n}",
+							"options": {
+								"raw": {
+									"language": "json"
+								}
+							}
+						},
+						"url": {
+							"raw": "localhost:8080/createJWT",
+							"host": [
+								"localhost"
+							],
+							"port": "8080",
+							"path": [
+								"createJWT"
+							]
+						}
+					},
+					"response": []
+				}
+			]
+		},
+		{
+			"name": "Health",
+			"request": {
+				"method": "GET",
+				"header": [],
+				"url": {
+					"raw": "localhost:8080/health",
+					"host": [
+						"localhost"
+					],
+					"port": "8080",
+					"path": [
+						"health"
+					]
+				}
+			},
+			"response": []
+		}
+	]
+}
\ No newline at end of file
diff --git a/src/gomazon/model/position.go b/src/gomazon/model/position.go
index 0b26aec5da50037c46818b642197c94134fa6d30..e5fc5d5d7d61f817a811c007f807e2d9318c053e 100644
--- a/src/gomazon/model/position.go
+++ b/src/gomazon/model/position.go
@@ -4,9 +4,9 @@ import "gorm.io/gorm"
 
 type Position struct {
 	gorm.Model
-	Amount         int     `gorm:"notNull"`
-	ProductId      uint    `gorm:"notNull"`
-	Price          float64 `gorm:"notNull"`
-	Totalprice     float64 `gorm:"notNull"`
-	ShoppingCartId uint    `gorm:"notNull"`
+	Amount     int     `gorm:"notNull"`
+	ProductId  uint    `gorm:"notNull"`
+	Price      float64 `gorm:"notNull"`
+	Totalprice float64 `gorm:"notNull"`
+	//ShoppingcartId uint    `gorm:"notNull"`
 }
diff --git a/src/gomazon/model/shopping_cart.go b/src/gomazon/model/shopping_cart.go
index 4964177f8a1f45705cebbb9dad696de5aee176c8..2c9f1db0469cb6e6d74184006b3ff31484b32f87 100644
--- a/src/gomazon/model/shopping_cart.go
+++ b/src/gomazon/model/shopping_cart.go
@@ -6,5 +6,5 @@ type ShoppingCart struct {
 	gorm.Model
 	Positions  []Position `gorm:"foreignKey:ID;constraint:OnUpdate:CASCADE,OnDelete:CASCADE"`
 	Totalprice float64    `gorm:"notNull;default:0.0"`
-	Username   string     `gorm:"unique"`
+	Username   string     `gorm:"notNull"`
 }
diff --git a/src/gomazon/service/bank.go b/src/gomazon/service/bank.go
index 7d4c4b631fc112328935aa9a0e8b7624a5a2672f..dae74b9d5691815795fdf5c88986b7fc1ab76a14 100644
--- a/src/gomazon/service/bank.go
+++ b/src/gomazon/service/bank.go
@@ -23,6 +23,11 @@ func (s *BankAccountService) CreateBankAccount(bankAccount model.BankAccount) (*
 		return nil, result.Error
 	}
 
+	if bankAccount.Balance < 0 {
+		log.Error("Balance must be a positive value")
+		return nil, fmt.Errorf("balance must be a positive value")
+	}
+
 	result = db.DB.Create(&bankAccount)
 	if result.Error != nil {
 		log.Error("Could not create Bankaccount")
diff --git a/src/gomazon/service/product.go b/src/gomazon/service/product.go
index 48a0b553e1e85d18a68ff71d6fbce9643dce6406..6f36cfb868a645373181103ae8c2633c1f29922e 100644
--- a/src/gomazon/service/product.go
+++ b/src/gomazon/service/product.go
@@ -10,6 +10,8 @@ type ProductService struct{}
 
 // Create Product
 func (s *ProductService) CreateProduct(Product model.Product) (*model.Product, error) {
+	var ratings []model.Rating
+	Product.Ratings = ratings
 	result := db.DB.Create(&Product)
 	if result.Error != nil {
 		log.Error("Could not create Product")
diff --git a/src/gomazon/service/rating.go b/src/gomazon/service/rating.go
index e0b7a53f09e96b45e57856956196f249dd09f873..9b02d7b25cef2a99956e6450d76879a7f4e22f62 100644
--- a/src/gomazon/service/rating.go
+++ b/src/gomazon/service/rating.go
@@ -25,6 +25,15 @@ func (s *RatingService) CreateRating(ProductID uint, Rating *model.Rating) error
 		log.Errorf("Error in CreateRating: GetProductByID failed")
 		return nil
 	}
+
+	Product.Ratings = append(Product.Ratings, *Rating)
+
+	result = db.DB.Save(&Product)
+	if result.Error != nil {
+		log.Error("Could not save Product")
+		return result.Error
+	}
+
 	// Recalculate Rating for this product
 	err = RecalculateTotalratingForProduct(Product)
 	if err != nil {
diff --git a/src/gomazon/service/shopping_cart.go b/src/gomazon/service/shopping_cart.go
index db8744596136aee51057dcca606b8043aa0c8ac7..f1139c9681621edb86ed4830d2b56292d98ee4d0 100644
--- a/src/gomazon/service/shopping_cart.go
+++ b/src/gomazon/service/shopping_cart.go
@@ -56,11 +56,11 @@ func (s *ShoppingCartService) AddProductToShoppingCart(username string, ProductI
 	gesPrice := Product.Price * float64(amount)
 
 	position := model.Position{
-		Amount:         amount,
-		ProductId:      Product.ID,
-		Price:          Product.Price,
-		Totalprice:     gesPrice,
-		ShoppingCartId: ShoppingCart.ID,
+		Amount:     amount,
+		ProductId:  Product.ID,
+		Price:      Product.Price,
+		Totalprice: gesPrice,
+		//ShoppingcartId: ShoppingCart.ID,
 	}
 
 	// Add position to shoppingcart