Can't find the database modeling features?
It is most likely that your edition of Microsoft Office Visio doesn't include the features you are looking for. To find out which edition of Visio you have, click About Microsoft Office Visio on the Help menu. The name of the edition is in the top line of text in the dialog box.
Microsoft Office Visio Standard does not include the Database Model Diagram template.
Microsoft Office Visio Professional supports the reverse engineering features for the Database Model Diagram template (that is, using an existing database to create a model in Visio) but it does not support forward engineering (that is, using a Visio database model to generate SQL code). For more information, see the topic, Reverse engineer an existing database.
If you are using the subscription version of Visio and want to learn about how to engineer an existing database into a database model, see the topic, Reverse engineer an existing database.
Note: You can find the full suite of database modeling features, including both reverse engineering and forward engineering, in Visio for Enterprise Architects. Visio for Enterprise Architects is included in MSDN Premium Subscription, which is available with Visual Studio Professional and Visual Studio Team System role-based editions.
See Also
Define a relationship in a Database Model diagram