# Self Doubt on ER diagram

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How to solve these type of questions https://gateoverflow.in/201404/er-diagram

Copying the image for quick reference:

Minimum no of tables.

My approach was:

First allocate all the relationships to entities (i.e decide on relationships)

So here R5 goes with E4 , R4 with E3, R2 with E2, R3 needs a separate table(relation) because of M:N, R1 for E2 as well.

Secondly see any tables can be merged.

E1E2 can be merged (only this is possible)

So finally tables will be E1R1E2R2, E4R5, E3R4, R3.

Correct me if I’m wrong. Let me know if there is a better process.

0

No need to merge E1 and E2... why would u do that?

Approach :

• First of all, count the no. of strong entity sets
• Count no. of multivalued attributes
• Count no. of weak entity sets
• Count no. of M : N relationship sets

## Related questions

1
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How 1:1 cardinality with total participation of atleast 1 entity needs min no. of tables = 1 ? 1:1 with partial participation of both entities needs min no of tables = 2?