Minimum number of tables for the given ER Diagram

Question

Answer 1

E1(A,B,C) with A is Candidate key and  C is mltivalue attribute 

R(A,D) with AD is candidate key

E2(D,E,F) with D is Candidate key and  F is mltivalue attribute .

To make relation in 1nf no multivalue attribute present in relation so 

E1 break in E1(AB) with Ais candidate key

E1 break in E1(AC) with AC is candidate key

E2 break in E2(DE) with D is candidate key

E2 break in E2(DF) with DF is candidate key

R(AD) will not combine with E1(AB) OR E2(DE). because\

when R(AD) will not combine with E1(AB) then E1(ABD) A->B AND AD WILL BE THEIR AD IS CANDIDAYTE KEY PARTIALY DEPENDANCY PRESENT SO NOT COMBINE.

SAME FOR R(AD) will not combine with E2(DE). 

SO 5 TABLE REQUIRED. ALL ARE KEPT ALONE

Comments

http://labe.felk.cvut.cz/~stepan/AE3B33OSD/Lesson08-IntroDatabases.pdf

THIS MAY HELP YOU.

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Thanks.

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If 1NF were given in the question what would be the answer then?

Answer 2

5 tables are required..

E1(A,B)

E1'(A,C)

E2(D,E)

E2'(D,F)

R(A,D)  as R is many to many relation candidate key is AD

Comments

Thanks. and can you provide the study material for this topic.

Answer 3

For Relation:-

           1:n ->No Table

           1:1 ->No Table

           M:N -> A Table required

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For Strong Entity:- 

            A table is required

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For Weak Entity:- 

                        A table is required

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For Multivalued Atrributes:-

                     A table is required

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Therefore in the above ER diagram:-

For Strong Entity-2

 For M:N   - 1

For Multivalued Attribute  - 2

total table:2+1+2=5

Comments

DONT GO BLINDLY BY THESE FORMULA

M:N 1 TABLE HOW?

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a employee can work on many projects and a project can have many employee.how many tables do you need to represent this relation?tell me

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MN FOR R RIGHT.

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if you will use D as a foreign key in E1 and A as Foreign key in E2 then since it is M:N relation in both of the table the attributes D and A will get more than one value in one tuple.Thats why we need another table.The new table will have AD as primary key