+========================================+
          |      DATABASE SYSTEMS PROJECT          |
          |           Phase II:                    |
          |     From ER (Conceptual) Model to      |
          |      Relational (Logical) Model        |
          +========================================+

The second phase of the project is to convert the E-R database
into a relational database. The specific tasks are described below:

Task of Phase II: 

2. Conceptual Database and Logical Database 

   - Briefly describe what each of section will do.

   2.1  E-R model and Relational model:
	2.1.1 Description of E-R model and relational model on
		- history about the model
		- what is the model
		- major features of the two models
		- Purpose of the models and others.

	2.1.2  Comparison of Two Different models
		- advantages and disadvantages
		- differences and similarities

   2.2  From Conceptual Datase to Logicl Database

       - Briefly decribe what we will do in this section.

  2.2.1 Converting Entity Types to Relations

        - Methods for converting
		- strong and weak entity.
		- entity types simple and composite attributes
		- entity types single and multi-valued attributes

	If more than one way of converting same type of items to relations, analyze and
	compare them.

  2.2.2	Converting Rrelationship Types to Relations 
	    
        - Methods for converting
 
		- Relationship types with one-to-one, one-to-many,
		  many-to-one and many-to-may relationships
		- 'IsA' (superclass and subclass) relationship
		- 'HasA' relationship
		- relationship type involving other relationship type
		- Recursive relationship (involving one entity type)
		- relationships involving more than 2 entity types
		- Relationship and Categories (or unions) types

	If more than one way of converting same type of items to relations, analyze and
	compare them.

  2.2.3 Database Constraints
   
	- Briefly describe what are contraints, purposes of contraints.
	- Define the following constraints and how a DBMS enforce
	  the contraints
		- Entity constraint
		- Primary key and unique key contraints.
		- Referenitial constraints
		- Check Constraints and Business Rules

  2.3. Convert Your E-R/Conceptual  Database into a Relational/Logical Database

       - describe what are the purposes of the section.

  2.3.1 Relation Schema for Your Local Database

	For each relation, specify the
		- attributes and their domain
		- all contraints (entity/primary key, referential, and business
		  constraints) that the relation may have.
		- Candidate keys.

   2.3.2. Sample Data of Relation

	Design relation instances (tuples, table body) for each relations.
	For relations which correspond to entity sets, give around 10 tuples.
	For relations which correspond to relationship sets, you should have
	more tuples/record (sat between 60-100 tuples).

   2.4.  Sample Queries to Your Database

       - describe what are the purposes of the section.

   2.4.1 Design Of Queries

     Refer to the questions on hotel database. Make around 10 non-trivial, but
     chanllenging queries.

     Try to use those words in your queries: largest, smallest, all, second largest, etc.
     That is, some queries must use division or set difference operation
     in relational algebra, and some queries need to use for-all and not-exist
     qualifiers in relational calculus.

     More specifically, you need to have at least 3 queries that need to use division operators
     in relational algebra and universisal (or not existential ) operator in relational calculus.

     NUMBER each of your queries in this section and following sections.

   2.4.2 Relational Algebra Expressions for Queries of 4.1

      - Briefly describe what is relational algebra.
      - Represent the queries in RA expressions 

   2.4.3 Tuple Relational Calculus Expressions for Queries

      - Briefly describe what is TRC
      - Represent the queries in TRC expressions 


   2.4.4 Domain Relational Calculus Expressions for Queries 

      - Briefly describe what is DRC
      - Represent the queries in DRC expressions 

In report of any new phase, the new report should contain all previous 
phases and the previous phases must be updated.