S.NXO, M.E. Data description language in the concept of multilevel structured description: DIAM 1I with FORAL. In Data Base Description, B.C.M. Dougue, and G.M. Nijssen, Eds., North-Holland Pub. Co., Amsterdam, pp. 239-258. ACM Transactions on Database Systems, Vol. 1, No. 1, March 1976.  Home/Search   Document Not in Database   Summary   Related Articles

.... There are four steps in designing a database using the entity relationship model: 1) identify the entity sets and the relationship sets of interest; 2) identify semantic information in the relationship sets such as whether a certain relationship This mapping information is included in DIAM II [24]. ACM Transactions on Dtabase Systems, Vol. 1, No. 1, March 1976. set is an 1 :n mapping; 3) define the value sets and attributes; 4) organize data into entity relationship relations and decide primary keys. Let us use the manufacturing company discussed in Section 3.1 as an example. The ....

....Jones Do they represent different entities (2) Only binary relationships are used in the entity set model, 5 while n ary relationships may be used in the entity relationship model. NO OF YEARS 20 ALT.IVE NAME l, NAME SAM JONES) I Fig. 22. The entity set view In DIAM II [24], n ary relationships may be treated as special cases of identifiers. ACM Transactions on Database Systems, Vol. 1, No. 1, Maroh 1970. 34 P.P. Chen THE ENTITYRELATIONSHIP THE ENTITY SET MODEL TERMINOLOGY ATTRIBUTE or ROLE ROLE NAME IDENTIFIER VALUE SET VALUE NTITY NAMESET NAME ....

S.NXO, M.E. Data description language in the concept of multilevel structured description: DIAM 1I with FORAL. In Data Base Description, B.C.M. Dougue, and G.M. Nijssen, Eds., North-Holland Pub. Co., Amsterdam, pp. 239-258. ACM Transactions on Database Systems, Vol. 1, No. 1, March 1976.

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