Talk:Cardinality (data modeling)

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Can't a doctor have multiple patients and a patient multiple doctors? Wouldn't the example mentioned then be of a many-to-many and not many-to-one type?

Well it seems to be correct there: there is a many-to-many example regarding doctors and patients and one-to-many between doctors and departments. Zeratul021 (talk) 21:12, 15 January 2009 (UTC)[reply]

In this article the relational model is mixed up with ER-Modeling! There is no n:m relationship between relational tables. In ER modeling the cardinality of a relationship type is a constraint that limits the number of potentially related entities.

In the relationsal data model the cardinality of a table is the number of tuples (rows) in that table. —Preceding unsigned comment added by 84.147.211.226 (talk) 21:02, 7 May 2010 (UTC)[reply]