Erwin Data Modeler Tutorial Notes:
1. Introduction to Erwin:
Definition: Erwin Data Modeler is a tool designed for data modeling, allowing users to visually design, generate, and manage databases.
Model Types: Supports various types of data models including logical, physical, and conceptual.
2. Getting Started:
Installation:
Ensure system requirements are met.
Follow installation guidelines and enter the license key when prompted.
User Interface:
Model Explorer: Displays the structure of your model.
Diagram Window: Visual representation of your data model.
Properties Window: View and edit properties of selected objects.
3. Creating a New Model:
Steps:
Go to File > New.
Select the type of model.
For physical models, specify the target database (e.g., Oracle, SQL Server).
Save Regularly: Use File > Save to save your progress.
4. Logical Data Modeling:
Entities:
Represent data objects or things you want to track information about.
Add attributes to entities to represent data elements or fields.
Relationships:
Define connections between entities.
Set cardinality (e.g., one-to-many).
Generalization & Specialization:
Represent "is-a" relationships.
Useful for capturing inheritance in data models.
5. Physical Data Modeling:
Tables:
Equivalent to entities in logical modeling but tailored to a specific DBMS.
Add columns to represent data fields.
Indexes:
Structures to improve query performance.
Can be unique or non-unique.
Keys:
Primary Key (PK): Uniquely identifies a record.
Foreign Key (FK): Links tables together.
6. Forward & Reverse Engineering:
Forward Engineering:
Convert logical models to physical models.
Generate SQL scripts to create the database.
Reverse Engineering:
Extract structures from an existing database to create a model.
Useful for documentation or to understand legacy systems.
7. Model Validation:
Purpose: Ensure the model is consistent and free from errors.
Process:
Use Erwin's built-in validation tool.
Review and address any issues or warnings.
8. Generating Reports:
Benefits: Documentation, stakeholder communication, and review.
Formats: Erwin can generate reports in HTML, RTF, XML, etc.
Customization: Tailor reports to include specific details.
9. Model Comparisons & Merging:
Comparison: Identify differences between models or between a model and a database.
Merging: Integrate changes from one model into another.
10. Collaboration & Version Control:
Team-Based Modeling: Multiple users can work on a model simultaneously.
Version Control: Track changes, maintain versions, and manage model history.
11. Advanced Features:
Naming Standards: Ensure consistency in naming conventions.
Macro Language: Automate repetitive tasks.
User-Defined Properties (UDPs): Add custom properties to model objects.
2. Getting Started with Erwin Data Modeler:
Installation:
System Requirements:
Operating System: Check the supported OS versions. Typically, Windows is supported, but the exact versions can vary.
Memory: Ensure you have sufficient RAM. The exact requirement might vary, but having at least 8GB is commonly recommended.
Disk Space: Ensure adequate free space. Installation might require several hundred MBs, but it's good to have additional space for models and backups.
Database Drivers: If you plan to connect Erwin to databases for reverse engineering or other tasks, ensure you have the necessary database drivers installed.
Installation Process:
Setup File: Run the Erwin Data Modeler installer (typically an .exe or .msi file).
Installation Wizard: Follow the on-screen prompts. Choose the installation directory and components you want to install.
License Key: During the installation, you'll be prompted to enter your license key. This key validates your purchase and determines the features available to you.
User Interface:
Model Explorer:
Purpose: Provides a hierarchical view of all elements in your data model.
Features:
Entities/Tables: Lists all the entities (for logical models) or tables (for physical models) you've created.
Relationships: Shows how entities or tables are related.
Domains: If you've defined domains (reusable attribute definitions), they'll be listed here.
Right-click Options: Right-clicking on objects in the Model Explorer often provides a context menu with actions like edit, delete, or generate reports.
Diagram Window:
Purpose: This is where you visually design and view your data model.
Features:
Drag & Drop: You can drag entities, attributes, and other objects onto the diagram. Relationships can be visually drawn between entities.
Zoom & Pan: Use zoom controls to focus on specific parts of your model. Panning allows you to navigate large models.
Layout Options: Erwin provides automatic layout options to organize your diagram neatly.
Properties Window:
Purpose: View and modify the properties of any object you select in the Model Explorer or Diagram Window.
Features:
Details: For an entity, you might see properties like name, definition, and notes. For an attribute, you might see properties like data type, default value, and domain.
Editing: Click on a property value to edit it. Some properties might have dropdown lists or other controls for easier input.