Developers whose are owner of the diagram or are members of the db_owner role of the database can open it to see or edit the diagram’s structure. When Developers working with SQL Server “Denali”, MS SQL Server 2008 R2 and MS SQL Server 2005 want to open a database diagram, they should follow the next steps:
1. In Object Explorer, expand the Database Diagrams folder.
2. Double-click the name of the database diagram they want to open.
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Right-click the name of the database diagram they want to open, and then choose Design Database Diagram.
The database diagram is opened in the Database Diagram Designer, from which they can edit the diagram.