You can create ER diagrams in Astah Professional edition.
ER Data Type
Astah has a set of ER Data Types that are often used, and you can choose one as a default type. In Astah, CHAR is set as default, so when you add an attribute to ER Entity, its data type would be CHAR.
How to add ER Data Type
The set of ER Data Types does not cover all the types in the RDBMS, so when you need one not listed,, you can add one by yourself. To do so,
(1) Go to [Tool] – [ER Diagram] – [Set ER Data Type] or select it from [ER Model] packages menu.
You can try out Astah Professional for free for 50 days to create ER Diagrams!