Exam 70-778 topic 1 question 115 discussion

Account to BrigdeAccount should be one to one, as "one account can be associated with one customer"

Relationship to bridge is 1-1

Bridge table is needed because there is no direct connection between Customer and Account table. So Bridge table behaves as a bridge between these 2 table and it contains all combinations of CustomerID from Customer table and AccountID from Account table. So Bridge table will look something like this: CustomerID AccountID Customer1 Account1 Customer1 Account2 Customer2 Account3 Customer1 appears 2 times because a customer can have multiple accounts. There is no possibility that there are duplicate AccountIDs in this Bridge table as an account can only be associated to one customer. So we can't have Customer2 Account2 Because Account2 is already assigned to Customer1. So relationship from Account to BridgeAccount will be: 1:1 (no duplicates) relationship from Customer to BridgeAccount will be: 1:many (duplicates) relationship from InsurancePolicy to Account will be: 1:1 (as each account is associated to only one insurance policy).

1-1 1-1 1-*

Regarding the following Link: https://docs.microsoft.com/en-us/power-bi/guidance/relationships-many-to-many#relate-many-to-many-dimensions Section: Relate many-to-many dimensions the Exam task 115 is similar to the Mircosoft Bank Account example where relations to a Bridge table are: 1-* Thats why I go with the given solution: 1. Relationship from InsurancePolicy to Account = One-to-one 2. Relationship from Account to BridgeAccount = One-to-many 3. Relationship from Customer to BridgeAccount = One-to-many Even from a the business logic it is strange that "account owner" cannot purchase multiple insurances with one account but this is not part of the question right? ;)

I go with: 1. one to one (refer to 2nd sentence, one Acct only related to one Single insurance policy) 2. one to many (1st of all, Bridge table always one to many, 2nd, Acct to Bridge, Account which means 1 particular insurance policy only apply to one customer, on the contrary, one customer can have various policies (life/health/death, blablabla...), absolutely one-to-many. 3. one to many, same explanation as 2. Nowadays, many-to-many relationship new solution (Cross Filter: This approach removes requirements for unique values in tables.): https://docs.microsoft.com/en-us/power-bi/transform-model/desktop-many-to-many-relationships

Well, I've never heard about a bridge table with one side 1-* and on the other side 1-1. Whenever you hear bridge table, it must be a one-to-many relationship to/from both sides. So, the last two are one-to-many, regarding to the first: The description says that an account is associated to one insurance. But one insurance could be associated to multiple accounts. I'd go with Many to one for the first one.

so what is the final answer???

You can have M-M now in PBI and the first sentence gives you the answer. A customer can have multiple accounts, 1-M. An account can only be associated to one customer 1-1. Each account is associated to only one insurance policy 1-1.

Customer Table ============================== CustomerID CustomerName c1 cust1 c2 cust2 BridgeAccount Table ============================== AccountID CustomerID ba1 c1 ba2 c1 Account Table ============================================================ AccountID AccountName CustomerID (virtual) ba1 accname1 c1 ba2 accname2 c1 InsurancePolicy Table ============================================================ PolicyID AccountID CustomerId (virtual) pol1 ba1 c1 pol2 ba2 c1 The correct answer according to the above relations; From InsurancePolicy to Account = One-to-one From Account to BridgeAccount = One-to-one From Customer to BridgeAccount = One-to-many

Relationship from InsurancePolicy to Account = Many-to-one Relationship from Account to BridgeAccount = One-to-many Relationship from Customer to BridgeAccount = One-to-many Based on ID relations

1- InsurancePolicy to Account (1:1) 2- Account to BridgeAccount (1:1) 3- Customer to BridgeAccount (1:*) TESTED

an account belong to one insurance policy, but n insurance policy could have multiple accounts Relationship from InsurancePolicy to Account = One-to-many Relationship from Account to BridgeAccount = One-to-one Relationship from Customer to BridgeAccount = One-to-many

The provided answer is correct. Customer 1 ---< * Bridge Account Bridge Account 1 --- 1 Account Account 1 --- 1 Insurance Policy

Why do we need a bridge table at all?

I vote for (One account may have multiples Insurance Policy) Relationship from InsurancePolicy to Account = Many-to-one Relationship from Account to BridgeAccount = One-to-one Relationship from Customer to BridgeAccount = One-to-many