1.自動增長的主鍵只能在創建表的時候設置
主鍵屬性設置IDENTITY(1,1)標示初始為1自動增長1
USE [Register] GO SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO CREATE TABLE [dbo].[Register]( [id] [int] IDENTITY(1,1) NOT NULL, [username] [nvarchar](50) COLLATE Chinese_PRC_CI_AS NULL, [password] [nvarchar](50) COLLATE Chinese_PRC_CI_AS NULL, [sex] [int] NULL, [picture] [nvarchar](max) COLLATE Chinese_PRC_CI_AS NULL, [IM] [nvarchar](50) COLLATE Chinese_PRC_CI_AS NULL, [information] [nvarchar](max) COLLATE Chinese_PRC_CI_AS NULL, [others] [nvarchar](max) COLLATE Chinese_PRC_CI_AS NULL, [ifisuser] [int] NULL, CONSTRAINT [PK_Register] 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]
