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


  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

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