SQL Server convert column to an identity column

Question

I am using SQL Server 2008. One int column I used as primary key but not identity column (whose value will be increased by 1 automatically). I want to convert this column to identity column. Any solutions?

thanks in advance, George

Answer 1

遗憾的是,您无法将字段更改为IDENTITY现有表.

你应该:

• 使用该IDENTITY字段创建一个新表
• 发行SET IDENTITY_INSERT ON新表
• 将数据插入新表
• 发行SET IDENTITY_INSERT OFF新表
• 放下旧桌子
• 将新表重命名为旧名称.

您可以使用SSMS更改字段类型,它将在幕后为您完成所有这些操作.

这是一个示例表:

CREATE TABLE plain (id INT NOT NULL PRIMARY KEY)

INSERT
INTO    plain
VALUES  (1000)

和脚本生成SSMS:

SET ANSI_PADDING ON
SET ANSI_WARNINGS ON
COMMIT
BEGIN TRANSACTION
GO
CREATE TABLE dbo.Tmp_plain
    (
    id int NOT NULL IDENTITY (1, 1)
    )  ON [PRIMARY]
GO
ALTER TABLE dbo.Tmp_plain SET (LOCK_ESCALATION = TABLE)
GO
SET IDENTITY_INSERT dbo.Tmp_plain ON
GO
IF EXISTS(SELECT * FROM dbo.plain)
     EXEC('INSERT INTO dbo.Tmp_plain (id)
        SELECT id FROM dbo.plain WITH (HOLDLOCK TABLOCKX)')
GO
SET IDENTITY_INSERT dbo.Tmp_plain OFF
GO
DROP TABLE dbo.plain
GO
EXECUTE sp_rename N'dbo.Tmp_plain', N'plain', 'OBJECT' 
GO
ALTER TABLE dbo.plain ADD CONSTRAINT
    PK__plain__3213E83F1A609306 PRIMARY KEY CLUSTERED 
    (
    id
    ) WITH( STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]

GO
COMMIT