ER Model DBMS

Question

Comments

2 relations?

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I think 4 tables are need from 2NF to BCNF. But for 1NF 1 table enough.

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@anu
there is a total participation from both side in E1 and E2, so E1, R and E2 can be merged together. and second table will be {A,C} for multivalued attribute.

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For 2NF. Yes but you see key is AD by combining since many to many relation . And A-B also present and D-> EF cause partial dependency . so need to break.

For 1NF there is no need to take saperate table for multivalue attrivute since 1NF can contain rudundancy.

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yes, you're correct! I think following tbles will be created:

R1={AC} (BCNF) CK={AC}
R2={AB} (BCNF) CK={A}
R3={AD} (BCNF) CK={AD}
R4={DEF} (BCNF) CK={D}
right?

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yes ....

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@Manu thakur there is a total participation from both side in E1 and E2, so E1, R and E2 can be merged together? How? as they have not given type of relation what if they are M:M relation? I don;t think they can be merged.

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Many to Many is given in ER diagram ryt ?

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@sandeep see the following example:Relationship is many to many with total participation at both sides and all three tables are merged together: