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Could someone help me with ER diagram? I need to transform ER diagram in to relational schema.

ER

Maybe someone can do it with comments I could understand?

reaanb
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Dizner
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  • post your diagram.. we can help – Raj More Feb 15 '17 at 16:23
  • Right now you are just asking for us to rewrite your textbook with a bespoke tutorial & do your (home)work & you have shown no research or other effort. Please see [ask], hits googling 'stackexchange homework' & the voting arrow mouseover texts. Show the steps of your work following your textbook with justification & ask 1 specific researched non-duplicate question re the first place you are stuck. Quote the definitions, theorems & algorithms you are relying on. All the steps are also SO faqs. – philipxy May 14 '20 at 21:54
  • Please [use text, not images/links, for text--including tables & ERDs](https://meta.stackoverflow.com/q/285551/3404097). Paraphrase or quote from other text. Give just what you need & relate it to your problem. Use images only for what cannot be expressed as text or to augment text. Images cannot be searched for or cut & pasted. Include a legend/key & explanation with an image. – philipxy May 14 '20 at 21:55

1 Answers1

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For every regular entity set (single-bordered rectangle), create a relation that contains each of that entity set's attributes. The primary key of the relation is indicated in the ER diagram.

For every relationship set (single-bordered diamond), create a relation that contains the primary keys of associated entity sets, as well as any dependent attributes of the relationship set. The primary key of the relation will be composed of the primary keys of those entity sets that aren't uniquely constrained (i.e. those with m or n cardinality indicators).

I see you have relationships that have the same entity set in more than one role. In these cases, the relation will contain a component ("column") for each role.

Don't create separate relations for identifying relationships (double-bordered diamonds). These would be redundant, since the relationship can be derived from the primary key of the relation for the associated weak entity set.

For a weak entity set (double-bordered rectangle), create a relation that contains the primary key of the parent entity set, the weak key of the child entity set, and any dependent attributes. The primary key of the relation will be composed of the parent entity set's primary key together with the weak key.

I'm not going to do it for you, but if you try it and post your attempt here, I'll be happy to give you feedback. If you need further explanation of any concept I mentioned here, feel free to ask.

reaanb
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