(ERD "Blog" 
     [Entity "Entry" 
     	  [Attribute "Title"  (StringDom Nothing) Unique False, 
     	   Attribute "Text"   (StringDom Nothing) NoKey False,
     	   Attribute "Author" (StringDom Nothing) NoKey False,
     	   Attribute "Date"   (DateDom Nothing) NoKey False],
      Entity "Comment"
        [Attribute "Text"   (StringDom Nothing) NoKey False,
         Attribute "Author" (StringDom Nothing) NoKey False,
         Attribute "Date"   (DateDom Nothing) NoKey False],
      Entity "Tag"
        [Attribute "Name" (StringDom Nothing) Unique False]
     ]
     [Relationship "Commenting"
       [REnd "Entry" "commentsOn" (Exactly 1),
        REnd "Comment" "isCommentedBy" (Range 0 Nothing)],
      Relationship "Tagging"
       [REnd "Entry" "tags" (Range 0 Nothing),
        REnd "Tag" "tagged" (Range 0 Nothing)]
     ]
)