CREATE TABLE [dbo].[user](
[userID] [int] IDENTITY(1,1) NOT NULL,
[fcode] [int] NULL,
[scode] [int] NULL,
[dcode] [int] NULL,
[name] [nvarchar](50) NULL,
[address] [nvarchar](50) NULL,
CONSTRAINT [PK_user_1] PRIMARY KEY CLUSTERED
(
[userID] ASC
)
) ON [PRIMARY]
GO
我该如何使用 t-sql
和/或 management studio
为列 fcode,scode,dcode
添加唯一约束?fcode,scode,dcode
必须共同具有唯一性。