ER Diagram to table 2

Question

Please Explain in detail i am weak in this topic

Comments

similar question:- https://gateoverflow.in/229580/madeeasy-test-series-number-of-tables-required

Answer 1

Four tables are required

Child(name,age,gender,ssn)

Dept(Did,dname,address,ssn)

Works(ssn,Did)

Emp(ssn,Ename,rating)

Answer 2

Three tables for three entities. For 1:N relationship no separate table is made. Below images might help. Any specific notation in your question that you don't understand?

 

Comments

Sir here two relations are defined in between same entities:- Manages and Works one with many to one and one with many to many.And in many to many there are three relation to build and in many to one only two so how did u proceed.

Sir can u tell me the approach to solve such question in deciding the number of relation for satisfying 1nf or 2nf. which critical points we need to keep in mind and how to tackle such problems. Its my weakest topic in dbms. I know the concept please see my comment in this question https://gateoverflow.in/216460/er-diagram-to-table-1

Only this much i know am i lacking up something please help me in this

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I considered Works relationship as 1:1 because it is shown as 1:1 in the ERD. I do agree Works relationship should be either many to many or many to one.

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works relationship is m:n and it is correctly shown in ER diagram

Answer 3

4 tables are required