多列的唯一约束

发布于 2024-09-14 07:54:36 字数 518 浏览 3 评论 0原文

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

如何使用 t-sql 和/或 management studio 为列 fcode、scode、dcode 添加唯一约束？ fcode、scode、dcode 一起必须是唯一的。

原文

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

How do I add a unique constraint for columns fcode, scode, dcode with t-sql and/or management studio? fcode, scode, dcode must be unique together.

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等往事风中吹 2024-09-21 07:54:36

如果该表已在数据库中创建，那么您可以稍后使用以下 SQL 查询添加唯一约束：

ALTER TABLE dbo.User
  ADD CONSTRAINT ucCodes UNIQUE (fcode, scode, dcode)

If the table is already created in the database, then you can add a unique constraint later on by using this SQL query:

ALTER TABLE dbo.User
  ADD CONSTRAINT ucCodes UNIQUE (fcode, scode, dcode)

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无所谓啦 2024-09-21 07:54:36

通过在创建表时使用约束定义，您可以指定一个或多个跨越多个列的约束。语法简化自 technet 文档，其形式为：

CONSTRAINT constraint_name UNIQUE [ CLUSTERED | NONCLUSTERED ] 
(
    column [ ASC | DESC ] [ ,...n ]
)

因此，结果表定义将是：

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]

By using the constraint definition on table creation, you can specify one or multiple constraints that span multiple columns. The syntax, simplified from technet's documentation, is in the form of:

CONSTRAINT constraint_name UNIQUE [ CLUSTERED | NONCLUSTERED ] 
(
    column [ ASC | DESC ] [ ,...n ]
)

Therefore, the resuting table definition would be:

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]

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初熏 2024-09-21 07:54:36

这也可以在 GUI 中完成。下面是向现有表添加多列唯一约束的示例。

在表格下，右键单击索引->单击/悬停新索引->单击非聚集索引...

将给出默认索引名称，但您可能想要更改它。选中唯一复选框，然后单击添加...按钮

检查您想要包含的列

单击“确定” 在每个窗口中，您就完成了。

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夜清冷一曲。 2024-09-21 07:54:36

USE [TSQL2012]
GO

/****** Object:  Table [dbo].[Table_1]    Script Date: 11/22/2015 12:45:47 PM ******/
SET ANSI_NULLS ON
GO

SET QUOTED_IDENTIFIER ON
GO

CREATE TABLE [dbo].[Table_1](
    [seq] [bigint] IDENTITY(1,1) NOT NULL,
    [ID] [int] NOT NULL,
    [name] [nvarchar](50) NULL,
    [cat] [nvarchar](50) NULL,
 CONSTRAINT [PK_Table_1] 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],
 CONSTRAINT [IX_Table_1] UNIQUE NONCLUSTERED 
(
    [name] ASC,
    [cat] 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

USE [TSQL2012]
GO

/****** Object:  Table [dbo].[Table_1]    Script Date: 11/22/2015 12:45:47 PM ******/
SET ANSI_NULLS ON
GO

SET QUOTED_IDENTIFIER ON
GO

CREATE TABLE [dbo].[Table_1](
    [seq] [bigint] IDENTITY(1,1) NOT NULL,
    [ID] [int] NOT NULL,
    [name] [nvarchar](50) NULL,
    [cat] [nvarchar](50) NULL,
 CONSTRAINT [PK_Table_1] 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],
 CONSTRAINT [IX_Table_1] UNIQUE NONCLUSTERED 
(
    [name] ASC,
    [cat] 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

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