questio2

Discussion 1 - Topic 1

Review the three different data models for a database described in the reference given below. The three models are a relational schema, a network model and a Hierarchical model

• Relational schema

EMPS (ENAME, SALARY)

MANAGERS (ENAME)

DEPTS (DNAME, DEPT#)

SUPPLIERS (SNAME, SADDR)

ITEMS (INAME, ITEM#)

ORDERS (O#, DATE)

WORKS_IN (ENAME, DNAME)

MANAGES (ENAME, DNAME)

CARRIES (INAME, DNAME)

PLACED_BY (O#, CNAME)

CUSTOMERS(CNAME,CADDR,BALANCE)

SUPPLIES (SNAME, INAME, PRICES)

INCLUDES (O#, INAME, QUANTITY) 

• Network model

• Hierarchical model

Part I

Construct an ERD of the database based on your understanding of the requirements shown in the graphical model.

• Post the ERD to the discussion and provide a brief description of the ERD.
  1. Include in the description business rules and integrity details.
     1. Entity types and relationships.
     2. Primary keys and foreign keys.

Part II

Write SQL to implement the relational database based on your ERD in Part I and execute the SQL in Oracle.