Microsoft Dynamics NAV Security
Microsoft SQL Server option –
External Microsoft SQL Server roles
Server Role (S) / Database Role (D)
Microsoft Dynamics NAV Activity
SysAdmin (S) or
SecurityAdmin (S) + db_Owner (D)
Invoking a Security Synchronization or Modifying the User table
SysAdmin (S) or db_Owner (D)
Creating Tables
within a Database
SysAdmin (S) or dbCreator (S) 
Or db_Owner (D) or db_ddladmin (D)
Altering a Database
SysAdmin (S) or dbCreator (S)
Or the user must be granted the Create Database permission + public access
to the Model DB
Creating a Database