https://i.stack.imgur.com/3wdI0.png
Please refer to the link above. Is 'billing_info' a weak entity as it depends completely on 'orders'? And if so, is 'bill_id' discriminator?
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the relationship in the link is a part of e-commerce website's E-R diagram – user2828552 Oct 17 '13 at 03:30
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See http://en.wikipedia.org/wiki/Weak_entity – user2864740 Oct 17 '13 at 03:32
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Do you mean billing_info ?@user2828552 – Tharindu Rusira Oct 17 '13 at 03:34
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Since billing has no meaning independent of the Order(as for billing, an order must be placed), it should be a weak entity. Please correct me if I m wrong. – user2828552 Oct 17 '13 at 03:37
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yes 'billing' is actually the 'billing_info' – user2828552 Oct 17 '13 at 03:41
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is 'billing_info' a weak entity? – user2828552 Oct 17 '13 at 03:54
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According to your diagram billing_info already have a primary key to identify its all records so its not a weak entity set.Additionally billing_info depends on orders only if all billing_info records are related with orders(total participation).
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