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Can a weak entity be dependent on another weak entity in ER-Model?

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This is an excerpt which i found on Quora that answered the question. But I still wanted to know few more things.

1. If there is no strong entity in the schema then can there be any relationship b/w 2 weak entities?

2. If two weak entities somehow participate in a relationship, is there any restrictions on the type of relationship they are involved in, like many-one/many-many/one-many/one-one.

3. Should there be always total participation between two weak entity relationship?

It would be better if an explanation is given along with an example.

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1 Answer

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i hope, 

Sheet is a Weak Entity w.r.to File but It is a Strong entity w.r.to Column,

if you are considering Sheet and Column only ===> it look like as normal dependency, strong entity ----> weak entity

 

if you considering File, Sheet and Column

then  key of Sheet relation in relation model ===> key of file+ partial key of sheet

then  key of Column relation in relation model ===> ( key of file + partial key of sheet ) + partial key of column

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