How to map ER to Relational Schema in DBMS

Steps to Draw relational schema

     Follow following steps to draw relational schema correctly,

1.       Match Regular Entities
2.       Match Weak Entities
3.       Match 1:1 Relations **
4.       Match 1:N Relations **
5.       Match N:M Relations **
6.       Match Multi-Value entities
7.       Match N'Arrays
8.       Match Recursive Relationship

How to Match Relations

     one to one (1:1) relationship

      you can put any side attribute to any side.

      

     Relational Schema

      

     one to Many (1:N) relationship

       Put one side primary key into many side.

     

       Relational Schema

    

      Many to Many (M:N) relationship

        Draw separate table for relation. Include each entities primary keys into that table

 Relational Schema

   

Article By - KGNP