将所有SQL Server列从BigInt更改为Int

Question

我继承了我需要使用的数据库.所有数字字段都设置为bigint(没有理由它们都是5000以下).

我怎样才能将big int的所有列都改为int？这是否可能导致任何现有约束等问题？

我只想更改表,只在我正在处理的特定数据库中.

我正在使用SQL Server 2008 R2

我需要为数百个字段执行此操作,我正在寻找可以运行一次的内容,它将对所有表字段执行所有更新.我想保留任何现有的约束,空状态和默认值.

因此,基本上数据库范围内的bigint更改为int而不更改除字段类型之外的任何内容.

谢谢

Answer 1

好吧,我遇到过这种问题.我不得不换int到bigint.这更难,但可能.使用以下语句更改数据类型非常容易:

Alter table myTable alter column targetcolumn int not null

但是,如果您的列涉及约束关系,则必须删除约束然后更改然后重新创建约束.

Alter table myTable drop constraint [fkconstraintname]
Alter table myTable alter column targetcolumn int not null
Alter table othertable alter column targetcolumn int not null
Alter table myTable add constraint [fkconstraintname] foreign key (targetcolumn) references othertable(targetcolumn)

编辑

如果你有很多限制,那么改变它是一个真正的痛苦.如果有很多表格有限制而且没有极端的改变,请不要这样做.

编辑

然后你可以做以下事情.通过Management Studio连接到Sql Server,右键单击必要的数据库=> Tasks => Generate scripts.

下一个=>下一步

那时按先进.会有一个弹出窗口.设置Type of data to script为架构和数据.选择适合您的输出(文件,查询窗口)？按确定继续.它将为您生成一个完整的DDL和DML,如下所示:

USE [master]
GO
/****** Object:  Database [Zafarga]    Script Date: 02/02/2012 19:31:55 ******/
CREATE DATABASE [Zafarga] ON  PRIMARY 

GO
ALTER DATABASE [Zafarga] SET COMPATIBILITY_LEVEL = 100
GO
IF (1 = FULLTEXTSERVICEPROPERTY('IsFullTextInstalled'))
begin
EXEC [Zafarga].[dbo].[sp_fulltext_database] @action = 'enable'
end
GO
ALTER DATABASE [Zafarga] SET ANSI_NULL_DEFAULT OFF
GO
ALTER DATABASE [Zafarga] SET ANSI_NULLS OFF
GO
ALTER DATABASE [Zafarga] SET ANSI_PADDING OFF
GO
ALTER DATABASE [Zafarga] SET ANSI_WARNINGS OFF
GO
ALTER DATABASE [Zafarga] SET ARITHABORT OFF
GO
ALTER DATABASE [Zafarga] SET AUTO_CLOSE OFF
GO
ALTER DATABASE [Zafarga] SET AUTO_CREATE_STATISTICS ON
GO
ALTER DATABASE [Zafarga] SET AUTO_SHRINK OFF
GO
ALTER DATABASE [Zafarga] SET AUTO_UPDATE_STATISTICS ON
GO
ALTER DATABASE [Zafarga] SET CURSOR_CLOSE_ON_COMMIT OFF
GO
ALTER DATABASE [Zafarga] SET CURSOR_DEFAULT  GLOBAL
GO
ALTER DATABASE [Zafarga] SET CONCAT_NULL_YIELDS_NULL OFF
GO
ALTER DATABASE [Zafarga] SET NUMERIC_ROUNDABORT OFF
GO
ALTER DATABASE [Zafarga] SET QUOTED_IDENTIFIER OFF
GO
ALTER DATABASE [Zafarga] SET RECURSIVE_TRIGGERS OFF
GO
ALTER DATABASE [Zafarga] SET  ENABLE_BROKER
GO
ALTER DATABASE [Zafarga] SET AUTO_UPDATE_STATISTICS_ASYNC OFF
GO
ALTER DATABASE [Zafarga] SET DATE_CORRELATION_OPTIMIZATION OFF
GO
ALTER DATABASE [Zafarga] SET TRUSTWORTHY OFF
GO
ALTER DATABASE [Zafarga] SET ALLOW_SNAPSHOT_ISOLATION OFF
GO
ALTER DATABASE [Zafarga] SET PARAMETERIZATION SIMPLE
GO
ALTER DATABASE [Zafarga] SET READ_COMMITTED_SNAPSHOT OFF
GO
ALTER DATABASE [Zafarga] SET HONOR_BROKER_PRIORITY OFF
GO
ALTER DATABASE [Zafarga] SET  READ_WRITE
GO
ALTER DATABASE [Zafarga] SET RECOVERY FULL
GO
ALTER DATABASE [Zafarga] SET  MULTI_USER
GO
ALTER DATABASE [Zafarga] SET PAGE_VERIFY CHECKSUM
GO
ALTER DATABASE [Zafarga] SET DB_CHAINING OFF
GO
EXEC sys.sp_db_vardecimal_storage_format N'Zafarga', N'ON'
GO
USE [Zafarga]
GO
/****** Object:  Table [dbo].[Category]    Script Date: 02/02/2012 19:31:56 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE TABLE [dbo].[Category](
    [CategoryId] [bigint] IDENTITY(1,1) NOT NULL,
    [CategoryName] [nvarchar](max) NULL,
PRIMARY KEY CLUSTERED 
(
    [CategoryId] 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
/****** Object:  Table [dbo].[Product]    Script Date: 02/02/2012 19:31:56 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE TABLE [dbo].[Product](
    [ProductId] [bigint] IDENTITY(1,1) NOT NULL,
    [Name] [nvarchar](max) NULL,
    [Price] [decimal](18, 2) NOT NULL,
    [CategoryId] [bigint] NOT NULL,
PRIMARY KEY CLUSTERED 
(
    [ProductId] 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
/****** Object:  ForeignKey [Category_Products]    Script Date: 02/02/2012 19:31:56 ******/
ALTER TABLE [dbo].[Product]  WITH CHECK ADD  CONSTRAINT [Category_Products] FOREIGN KEY([CategoryId])
REFERENCES [dbo].[Category] ([CategoryId])
ON DELETE CASCADE
GO
ALTER TABLE [dbo].[Product] CHECK CONSTRAINT [Category_Products]
GO

适当更改所有数据类型,然后运行.

如你所说,你所有的数据都低于5000行.因此无需修改insert语句.

准备好了需要很长时间.希望这很有用.

编辑

这将生成一个新数据库,因此请准备重命名原始或新创建的数据库.