When you set Data Type to ER Entity’s attributes in Astah, you can choose it from the [Data Type] list in the [Base] tab of Attribute’s property view.
If you cannot find the one you want, you can always add from [ER Data Type] menu. Here is an example of adding one – [VARCHAR2].
- Launch Astah and go to [Tool] – [ER Diagram] – [Set ER Data Type]
- Click [Add] on the [Set ER Diagram Data Type] dialog
- Enter [VARCHAR2] for Data Type Name and the click [OK]. You can set property for the length and precision of data too.
- That’s it. Now [VARCHAR2] is in the list!