Database decomposition strategy in Microservices - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a microservice with its own database.

Microservices

class [1]Service:
    def __init__(self):
        self.database = DatabaseConnection('user_db')

Drag options to blanks, or click blank then click option'

AUser

BOrder

CInventory

DPayment

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing a service that does not manage user data.

The UserService manages user data and thus connects to the 'user_db' database.

2fill in blank

medium

Complete the code to route a request to the correct microservice based on the database decomposition.

Microservices

def route_request(request):
    if request.type == 'order':
        return [1]Service.handle(request)

Drag options to blanks, or click blank then click option'

AUser

BPayment

COrder

DInventory

Attempts:

3 left

💡 Hint

Common Mistakes

Routing order requests to UserService or unrelated services.

OrderService handles requests related to orders, so the routing directs order requests there.

3fill in blank

hard

Fix the error in the database access code for the Inventory microservice.

Microservices

class InventoryService:
    def get_stock(self, item_id):
        return self.db.[1]('SELECT stock FROM inventory WHERE id = %s', item_id)

Drag options to blanks, or click blank then click option'

Acommit

Bexecute

Cfetchall

Dconnect

Attempts:

3 left

💡 Hint

Common Mistakes

Using fetchall before execute, or commit/connect incorrectly.

The execute method runs the SQL query; fetchall retrieves results. Here, execute is needed first.

4fill in blank

hard

Fill both blanks to correctly implement database decomposition with separate connections and queries.

Microservices

class [1]Service:
    def __init__(self):
        self.db = DatabaseConnection('[2]_db')

Drag options to blanks, or click blank then click option'

APayment

Buser

Corder

DInventory

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing service names and database names incorrectly.

PaymentService connects to 'user_db' in this example, showing database decomposition by service.

5fill in blank

hard

Fill all three blanks to implement a query filtering orders by status in the Order microservice.

Microservices

def get_orders_by_status(self, status):
    query = "SELECT * FROM orders WHERE status [1] %s"
    self.db.[2](query, (status,))
    return self.db.[3]()

Drag options to blanks, or click blank then click option'

A=

Bexecute

Cfetchall

Dcommit

Attempts:

3 left

💡 Hint

Common Mistakes

Using commit instead of execute or fetchall, or wrong SQL operator.

The query uses '=' to filter by status, execute runs the query, and fetchall retrieves the results.