Transcription of ER & EER to Relational Mapping
{{id}} {{{paragraph}}}
Example: dental hygienist
ER & EER to Relational Mapping
Chapter 91ER & EER to Relational Mapping Addison Wesley Longman, Inc. 2000, Elmasri/Navathe, Fundamentals of database Systems, Third EditionNumberFnameDEPENDENTM initLnameNameAddressSexSalarySsn___EMPLO YEEB dateWORKS_FORS tartDateMANAGESN umberOfEmployeesNameLocationsDEPARTMENTC ONTROLSPROJECTNameLocationNumber_____WOR KS_ONDEPENDENTS_OFN1 HoursNNameSexBirthDateRelationshipN11 NsupervisorsuperviseeSUPERVISION11N1 Figure diagram for the company 92 Step 1:For each regular entity type E Create a relation R that includes all the simple attributes of E. Include all the simple component attributes of composite attributes. Choose one of the key attributes of E as primary key for R. If the chosen key of E is composite, the set of simple attributes that form it will together form the primary key of R. Addison Wesley Longman, Inc. 2000, Elmasri/Navathe, Fundamentals of database Systems, Third EditionDNAMEDEPARTMENTDNUMBERMGRSSNMGRST ARTDATEFNAMEMINITLNAMESSNBDATEADDRESSSEX SALARYSUPERSSNDNOEMPLOYEEDEPT_LOCATIONSD NUMBERDLOCATIONPNAMEPROJECTPNUMBERPLOCAT IONDNUMESSNWORKS_ONPNOHOURSDEPENDENTESSN DEPENDENT_NAMESEXBDATERELATIONSHIPF igure diagram for the COMPANY relationaldatabase schema; the primary keys are 93 Step 2:For each weak entity typeWwith owner entity type E Create a relation R, and include all simple attributes and simple components of composite attributes of W as attributes of R.
relational database schema; the primary keys are underlined. DEPT_LOCATIONS. DNUMBER DLOCATION. Chapter 9 8. Step 7: For each . n-ary relationship type R, n>2 • Create a new relation S to represent R. • Include as foreign key attributes in the S the primary keys of the relations that represent
Tags:
Information
Domain:
Source:
Link to this page:
Please notify us if you found a problem with this document: