Structuring Database for Accounting

to provide a step-by-step procedure that transforms ER design into Relational Data model design to constitute the desired database. In the context of ER model as shown in design figure14. , the following specific steps are required to cause its transformation into relational data model : (i) Create a relation for every strong entity : For each strong entity type (which has primary key) in ER schema, a separate relation that includes all the simple attributes of that entity is created. Either choose one of the key attributes of such an entity as the primary key for this relation , or choose a set of simple attributes that uniquely identify this entity as the primary key of the relation so created.

For example, employee entity is strong because it finds its primary key in EmpId which is one of its unique attribute. Therefore, a separate relation for Employee has been created as Employee (EmpId, Fname, Minit,Lname,Address, PhoneNo, SuperId) Similarly, separate relations need be created for the following strong entities whose Primary Key attribute have been underlined. Vouchers (VNo,vDate, amount, narration) (ii) Create a separate relation for each weak entity type : Every weak entity