Many-to-many relationship, Database Management System

For each m:n relationship type R, we make a new table (say S) to represent R. We also contain the primary key attributes of both the participating entity types as a foreign key attribute in S. Any easy attributes of the m:n relationship type (or easy components of a composite attribute) is also contain as attributes of S.

For example, the m: n relationship taught-by among entities COURSE and FACULTY should be shown as a new table.  The structure of the table will contain primary key of COURSE and primary key of FACULTY entities

A new table TAUGHT-BY will be created as: Primary key of TAUGHT-By table

 

ID

 

Course_ID

 

{Primary key of FACULTY table}

 

{Primary key of COURSE table}

 

 

Please note that since there are no attributes to this relationship, thus no other fields.

Posted Date: 3/6/2013 6:27:46 AM | Location : United States







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