Er diagram

Question

Comments

I think 1 would be the ans but given ans is 4 .Please correct me if I am wrong

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The answer is 4.

3 for Entity and 1 for Multivalued Attribute.

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@dkm

is there any problem if we merge two or more tables?

Because FDs are not given and they talk only for 1nf.

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Here is the rule (https://db.grussell.org/section006.html#_Toc67114436):

To map 1:m relationships, the primary key on the `one side' of the relationship is added to the `many side' as a foreign key.

So simply merge the relations to the many side(N) even when it is total participation on both the side. Therefore,

3 table for Entity and Relation.

1 table for Multivalued Attribute in entity Bank.

Answer 1

Table 1: Bank(Code, Ph_No)

Table 2: Bank_Branches_BankBranch(Code, Name, Addr, Branch_No, BB.Addr)

Table 3: Loan_Loans(Loan_No, Amount, Type, Branch_No)

According to me there should be 3 tables

Please correct me where I'm wrong

Comments

Multivalued and composite both type of attributes are not allowed in 1nf. So for multivalued attributes 1 extra table is required.

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Composite attribute will require separate table for 1NF due to atomicity property but for multivalued attribute it can be there in same table as atomicity property is preserved though there'll be redundancy.

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No..

Composite attributes can be broken into simple attributes and present in the same table whereas for multivalued attribute we require seperate table..

Answer 2

THE MINIMUM TABLE WILL BE 4 .  3 FOR ENTITY AND 1 FOR MULTIVALUED ATTRIBUTE(REMEMBER IN 1NF ALL THE ATTRIBUTE MUST BE ATOMIC BUT BANK NAME IN ABOVE QUESTION IS MULTIVALUED ATTRIBUTE SO WE HAVE TO CREATE EXTRA TABLE FOR THAT)

Comments

it can still be merged even with 1:n relationship because of total participation on both sides

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in case of 1:n relationship table can be merged unnecessarily when in question it is asked about maximum table.

if there are two entity in 1:n relationship then it can be merged with the primary key of both sides in the new table referring to original table(acting as foreign key)but in that case 3 table will be needed .

but share me if anywhere if it is mentioned but i m sure that your procedure is possible for 1:1 relationship only.

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https://gateoverflow.in/77410/doubt

please go through this