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Exercises31employee(person-name, street ,c ity)works(person-name,company-name,salar y)company(company-name, city )manages(pers on-name,manager-name) relational database for Exercises , and 2, we sawhowto representmany-to-many, many-to-one, one-to-many, suchrelationship setsin the :Supposethe primarykeyof relation schema is 1 2 n andthe primarykeyof relationschema is 1 2 m .Thenare-lationshipbetweenthe2 setscan be representedas a tuple( 1 2 n 1 2 m). Ina one-to-onerelationship, each valueon 1 2 n willappear inexactlyonetupleandlikewisefor 1 2 m .Inamany-to-onerelationship( ,many -one ), eachvalue on 1 2 n willappearonce,and eachvalueon 1 2 n may appear manytimes. Inamany-to-manyrelationship, values on both 1 2 n and 1 2 m will appearmany times. However, in all the above cases 1 2 n, 1 2 m is a primarykey, sono tupleon ( 1 n 1 m) willappearmore database of Figure , where theprimary keysare un-derlined.

represent such relationship sets in the relational model. Answer: Suppose the primary key of relation schema is 1 2 n and the primary key of relation schema is 1 2 m.Thenare-lationship between the 2 sets can be represented as a tuple ( 1 2 n 1 2 m). In a one-to-one relationship, each value on 1 2 n

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