In Astah Professional, you can easily convert your UML models to ER models.
Convert UML to ER Diagram Models

Convert Class diagram to ER diagram

You can convert your UML Class diagram into the ER diagram with one-click.

  1. Select [Convert to ER Diagram] from the Class diagram’s pop-up menu in the tree view.
    Convert UML to ER Diagram
  2. Now the ER diagram will be created and appears in the tree.
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Convert rules

Compositions to Identifying Relationship

Any composition relationships will be converted to Identifying-Relationship.
Convert Class to ERD

Associations to Identifying relationship

In order to convert association to Identifying relationship, Add “identifying” stereotype to the association and let it have “one-to-many” multiplicity.
Converting Identifying relationship

Associations to Non-Identifying Relationship

In order to convert an association to a Non-Identifying relationship, add “Non-identifying” stereotype to the association and let it have “one-to-many” multiplicity.
Converting non-identifying relationship

Data Type

UML Class’s attributes’ will be converted to ER Entity’s data type as shown in the table below.

UML Attribute type

Convert to

boolean, bool, System.BooleanBIT
long long, char, unsigned long long, wchar, octet, sequence,
wstring, object, signed char, unsigned char, wchar_t
byte, int, long, short, sbyte, uint, ulong, ushort, unsigned short,
short int, signed short int, unsigned short int, signed int,
unsigned int, unsigned long, long int, signed long int, unsigned long int,
java.sql.Date, java.util.Date, System.DateTimeDATE
double, long double, System.DoubleDOUBLE PRECISION
decimal, System.DecimalDECIMAL
string, System.String, java.lang.StringVERCHAR

Convert UML to ERD

In Astah Professional, you can convert all UML models in a project file to ER models at once.

  1. Go to [Tools] – [ER Diagram] – [Convert UML Model to ER Model].
    Converting UML diagram to ER Diagram
  2. Select which UML models to convert to ER models and click [OK].
    Choosing which UML model to ER Diagram model