Problem:
You need to add a primary Key to a table.

Solution:
Heres a few types I've run across.

Manual Primary Key

CREATE TABLE [dbo].[HtmlDtos]([Id] [int] PRIMARY KEY)

Auto Sequential Int Primary Key

CREATE TABLE [dbo].[HtmlDtos]([Id] [int] IDENTITY(1,1) PRIMARY KEY)

Auto Sequential GUID PK

CREATE TABLE [dbo].[HtmlDtos] ([Id] UNIQUEIDENTIFIER DEFAULT NEWSEQUENTIALID() PRIMARY KEY)

Auto Random GUID PK

CREATE TABLE [dbo].[HtmlDtos]([Id] UNIQUEIDENTIFIER DEFAULT NEWID() PRIMARY KEY)