1. ERwin

2. Main Screen

3. Create a New Model Create a new logical/physical model
2. Click “Logical/Physical”
1. Click “Create model”
(or File -> New)
3. Configure the “Target Database”
(In CS360, we’re using Oracle 11g)

4. Differences between Notations
Image from
President
Company
max=1
min=0
min=1
Person
Location
max1
<Crow’s Foot>

5. Notations Two notations available Information Engineering (IE)
Integration DEFinition (IDEF)
Use IE Notation
IE notation
To use IE Notation (in menu bar)
Model → Model Properties
Logical
Physical
IDEF1X notation
Logical
Physical

6. Information Engineering Notation

7. Entity Sets Entity set name Entity set Keys Attributes
Left click  attribute properties
Entity set name
Keys
Attributes
An independent entity set
Entity set
For relationships
and weak entity sets
A dependent entity set (Stars-in)

8. Entity Sets (Cont’d) Non-Identifying vs. Identifying Relationship
Non-Identifying relationship
Independent Entity Sets
Dependent Entity Sets

9. O: zero, |: one, crow’s foot: many
Relationships
O: zero, |: one, crow’s foot: many
relationships
Example
Movies
Owns
Studios
Identifying relationship
Many-to-many relationship
Non-identifying relationship

10. Configure cardinality
Relationships
Relationship properties
Null allowed
[c.f.) if not allowed ]
Configure cardinality
Three cardinality options
zero, one or more (above example)
One or more
Zero or one

11. Relationships (Cont’d)
Convert many-to-many relationships to connecting entity sets
1. Click many-to-many relationship
2. Click “many-to-many transform”
3. Transformed relationship
4. (optional) change entity name

12. Subclasses 1. Click “sub-category” icon (isa relationship)
2. Click the superclass
(optional)
4. Click is-a relationship
(after clicking “sub-category” icon)
(optional)
5. Click the subclass
3. Click the subclass

13. Subclasses choose the strategy for converting “isa-relationship”
Three options (see lecture note)
1. Supertype-Subtype Identity (E/R view)
2. Supertype-Subtype Rolldown (Similar to Object-oriented approach, but not equal)
3. Supertype-Subtype Rollup (Using NULL values to combine relations)
1. Click “isa” symbol!
2. Select
transformation
policy

14. DB Schema Construction (Cont’d)
Step 2 (cont’d)
Three options
1. Supertype-Subtype Identify (E/R view)
2. Supertype-Subtype Rolldown (Similar to Object-oriented approach, but not equal)
3. Supertype-Subtype Rollup (Using NULL values to combine relations)
Option 1
Option 2
Option 3

15. ER modeling Two different models Logical model Physical model
Conceptual modeling
Independent of DBMS-specific implementations
Only support subclasses and simple data types
Physical model
DBMS-specific modeling
DBMS-specific data types

16. Buttons for generating DB schemas
ER modeling (Cont’d)
Two different models (Cont’d)
Buttons for generating DB schemas
DB-specific
Data types
Logical model
Physical model

17. DB Schema Construction
Step 1: Create a logical model
Draw your ER diagram

18. DB Schema Construction (Cont’d)
Step 2: In physical model, choose a proper DB-specific data type for each columns in tables
Right click an Entity  select Column
Define data types for each column

19. DB Schema Construction (Cont’d)
Step 3: In physical model, generate a script for constructing schemas to the target DB (e.g. Oracle)
Forward engineering
(construct schema)
Click “Preview button” to verify your SQL statements

20. ERwin Tip Display configuration Right click background
Check options you want to display on ER diagram
 Entity, Table, Relationship …
Here’s a tip solving a problem