ER Diagram

With Astah Professional, you can create ER Diagrams (Entity-Relationship Diagrams) in IDEF1X or IE notations.
Also, you can auto-generate ER diagrams by reversing from your database. All models are stored in one place and can be converted to other models like UML Class diagram models and vice versa.

Creating ER Diagram

1. Go to [Diagram] – [ER Diagram] from Main Menu.
   
   
   
2. In the tree view, the Domain and ER Diagram will be created under the [ER Model] package.
   

Auto-generate ER Diagram

You can generate ER Diagrams after importing database tables with DB Reverse Plug-in.

1. Right-click on the target ER Model in the Tree and select [Auto Create ER Diagram].
   
   
   
2. Generated ER Diagram will open automatically.
   

Logical and Physical name

Each model has two fields for its name – Logical and Physical and you can change the name to display on the diagram.


There are three ways to switch the name.

1. Right-click on the diagram and select [Diagram Model Type] from its pop-up menu.


2. Click [Diagram Model Type] in the Structure Tree.


3. Switch from ER Diagrams’ Property View (Bottom-left pane).

TIPS – Set default name type

You can set logical or physical name as default in the [Tools] – [System Properties] – [ER Diagram].

Switch Notations  [IDEF1X] and [IE]

You can switch the diagram notation between [IDEF1X] and [IE]. There are two ways to switch the notation.

1. Right-click on the ER diagram and click [Diagram Notation] from its pop-up menu.


2. Switch from ER Diagram’s Property View (bottom-left pane.

Domains

Add a single ER Domain

You can create ER Domains from pop-up menu of [Domain] in the tree view.

Add plural ER Domains

You can also add more than one ER Domain at once.

1. Click [Add ER Domains] in the tree view or go to [Tools] – [ER Diagram] – [Add ER Domains].

2. Specify the domain data in the list.

Add domain to an ER Entity

You can drag a Domain from the Tree to an ER Entity directly on the diagram.

Relationships

Select Identifying Relationship, Non-Identifying Relationship or Many-to many Relationships from the Tool palette and click two Entities to connect.

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

1. Choose which type of relationship you want to create.
   
   
   
2. Click two Entities.
   
   
   
3. The relationship is now created. Foreign keys would be automatically added depending on the relationship type.
   
   

SQL Export

1. You can export ER Entities into SQL (SQL-92). To export, go to [Tools] – [ER Diagram] – [SQL Export], then select Entities you want to export.
   
   
2. [SQL Export] Dialog opens. Specify the location where you want to export to.
   
   
   
3. In the [Option], you can specify more detailed settings.
   

TIPS: Export Entity Definition as a comment

You can export the Entity’s definition as a comment by configuring so in the [Option] menu.

ER Data Type

1. Go to [Tools] – [ER Diagram] – [Set ER Data Type] from main menu.
   
   
   
2. Click [Add] button to add a new ER Data type.
   
   
   
   
3. Enter the new Data Type in this dialogue and click [OK].
   

TIPS: Set Default Data Type

You can set the default Data type for an Entity attribute by marking it at [Default Type].

Export Entity Definition Report

You can export a list of ER Domains, Entities and each Entity’s detailed information to Excel file.

1. Go to [Tools] – [ER Diagram] – [Export Entity Definition Report].


2. A list of domains, entities and each entity information would be exported.


3. Enter the new Data Type in this dialogue and click [OK].

Export format of Attributes and its TaggedValues