Wednesday, February 9, 2011

what is cardinality and degree of relation?

The number of rows is the cardinality of the relation, and the number of columns is the degree

2 comments:

  1. Cardinality of a Relationship

    Relationship cardinality specify how many of each entity type is allowed. Relationships can have four possible connectivities as given below.

    One to one (1:1) relationship
    One to many (1:N) relationship
    Many to one (M:1) relationship
    Many to many (M:N) relationship

    Taken from http://www.softwaredevelopersworld.com/db/rdbms/c1/design.php

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  2. Point to be noted here,Relation and Relationship are different!!!

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