(
  TagID uniqueidentifier ROWGUIDCOL not null 
    default NewID()
  constraint PK_Tag primary key clustered,
  [Text] nvarchar(100) not null
)

create table dbo.FilesTags
(
  FileID uniqueidentifier not null,
  TagID uniqueidentifier not null,
    constraint PK_FilesTags
      primary key clustered (FileID, TagID),
    constraint FK_FilesTags_Files
      foreign key(FileID)
      references dbo.Files(FileID)
      on delete cascade,
    constraint FK_FilesTags_Tags
      foreign key(TagID)
    references dbo.Tags(TagID)
)