Unique constraint on multiple columns
WE can make it with Table Query
OR :
- <code>
- 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
- ),
- CONSTRAINT [UQ_codes] UNIQUE NONCLUSTERED
- (
- [fcode], [scode], [dcode]
- )
- ) ON [PRIMARY]
- </code>
- <code>
- ALTER TABLE dbo.User
- ADD CONSTRAINT ucCodes UNIQUE (focde, scode, dcode)
- </code>