ER Diagram

Astah Professional allows you to create and manage Entity-Relationship Diagrams (ER Diagrams) using IDEF1X or IE notation. You can also auto-generate ER diagrams by reverse-engineering tables from your database.

Because all models are stored centrally, you can easily convert ER models into other formats, such as UML Class Diagrams.

Creating ER Diagram

1. Go to [Diagram] – [ER Diagram] from the main menu.
   
   
   
2. An ER Diagram will be created under the [ER Model] package in the Structure Tree.
   

Auto-generate ER Diagram

You can automatically generate ER Diagrams by importing database tables using the DB Reverse Plug-in.

1. Right-click the target ER Model in the Structure Tree.
2. Select [Auto Create ER Diagram].
3. Choose your preferred generation method.
   
   
   
4. The diagram will be created and opened automatically.

Logical and Physical name

Astah allows you to manage both Logical and Physical names for entities.

There are three ways to switch between displaying logical and physical names:

1. Right-click on the diagram background and select [Diagram Model Type].
   
2. Click [Diagram Model Type] in the Structure Tree.
   
3. Switch it in the ER diagram’s Property View (bottom-left pane).
   

TIP: You can set the default name type in [Tools] → [System Properties] → [ER Diagram].

ER Entity

Creating ER Entities

Astah provides several ways to create ER Entities – please refer to the Diagram Editor page.

Adding Primary Keys and Attributes

There are multiple ways to add Primary Keys and Attributes to ER Entities:

Using the Suggest Feature:

Hover over an ER Entity to reveal mini icons.

• Click the red diamond to add a Primary Key.
• Click the orange diamond to add an Attribute.
  

Once you add an item, press [Enter] to create another.

Alternatively, you can add Primary Keys and Attributes by pasting text.

Display Level and Extended Visibility

There are three display levels for ER Entities: Entity, Primary Key, and Attribute.

To change the level, right-click an ER Entity and select [Display Level] from the menu.

To show additional details such as data types and lengths, select [Extended Visibility] from the context menu and check the items you wish to display.

TIPS: You can set the default display settings in [Tools] → [System Properties] → [ER Diagram].

Managing Domains

Creating a Single Domain

Right-click [Domain] in the Structure Tree and select [Add ER Domain].

Creating Multiple Domains

You can add multiple domains at once:

1. Right-click [Domain] in the Structure Tree and select [Add ER Domains], or go to [Tools] > [ER Diagram] > [Add ER Domains].
   
2. A domain configuration window opens. Click the [Add] icon on the right and enter the details for each domain in the list provided.
   

Applying a Domain to an Entity

To apply a domain, drag it from the Structure Tree and drop it directly onto an ER Entity in the diagram.

Relationships

You can create relationships using the Tool Palette. Select the desired relationship type and click the two Entities you wish to connect.

Available Relationship Types

IDEF1X	IE	Relationship type
		Identifying Relationship
		Non-Identifying Relationship
		Many-to-many Relationship

1. Hover over the first ER Entity to reveal a mini icon. Click it and select a relationship type.
   
2. Click the second ER Entity.
   
3. The relationship is created, and Foreign keys are automatically generated based on the relationship type.
   

SQL Export

You can export ER Entities into SQL (SQL-92).

1. Go to [Tools] > [ER Diagram] > [Export sql].
2. In the dialog that opens, specify which models to export and the export location, then click [Export].
   
3. In [Option], you can specify more detailed settings.
   

TIPS: Export Entity Definition as a comment

You can export each Entity’s definition as a comment by enabling it in the [Option] menu.

Managing ER Data Types

1. Go to [Tools] – [ER Diagram] – [Set ER Data Type] from the main menu.
   
2. Click the [Add] button to create a new data type.
   
   
   
3. Enter the Name and parameters for the data type, then click [OK].
   

TIPS: To set a specific data type as the default for new Attributes, check the [Default Type] box when creating or editing it.

Export Entity Definition Report

You can export a comprehensive list of ER Domains, Entities and detailed Entity information to an Excel file.

1. Go to [Tools] – [ER Diagram] – [Export Entity Definition Report].
   
2. Check the models you want to include in the report, then specify the save location and file name. Click [Export] to generate the Excel file.
   
   

Export format of Attributes and its TaggedValues