CREATE TABLE [dbo].[Tab_utenti](
  [Id] [int] NOT NULL,
  [Utente] [varchar](30) NULL,
  [Idcategoria] [smallint] NULL,
  [Idcomune] [smallint] NULL,
  [Indirizzo] [varchar](50) NULL,
  [Telefono] [varchar](15) NULL,
  [Fax] [varchar](15) NULL,
  [Cellulare] [varchar](15) NULL,
  [Email] [varchar](50) NULL,
  [Website] [varchar](50) NULL,
  [Username] [varchar](20) NULL,
  [Password] [varchar](20) NULL,
  [Referente] [varchar](30) NULL,
 CONSTRAINT [Chiaveprimaria] PRIMARY KEY CLUSTERED 
(
  [Id] ASC
)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY]
) ON [PRIMARY]

GO

Calcola che utente,idcategoria,idcomune sono indici:

CREATE NONCLUSTERED INDEX [Utente] ON [dbo].[Tab_utenti] 
(
  [Utente] ASC
)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, SORT_IN_TEMPDB = OFF, IGNORE_DUP_KEY = OFF, DROP_EXISTING = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY]
GO


CREATE NONCLUSTERED INDEX [Categoria] ON [dbo].[Tab_utenti] 
(
  [Idcategoria] ASC
)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, SORT_IN_TEMPDB = OFF, IGNORE_DUP_KEY = OFF, DROP_EXISTING = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY]
GO

CREATE NONCLUSTERED INDEX [Comune] ON [dbo].[Tab_utenti] 
(
  [Idcomune] ASC
)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, SORT_IN_TEMPDB = OFF, IGNORE_DUP_KEY = OFF, DROP_EXISTING = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY]
GO