SQL Server将列转换为标识列

很遗憾,不能将字段更改为 IDENTITY 在现有表上。

你应该:

• 身份
• SET IDENTITY_INSERT ON
• 将数据插入新表
• 发行 SET IDENTITY_INSERT OFF
• 放下那张旧桌子
• 将新表重命名为旧名称。

你可以用 SSMS

CREATE TABLE plain (id INT NOT NULL PRIMARY KEY)

INSERT
INTO    plain
VALUES  (1000)

以及由 SSMS系统 :

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

在sql server的“对象资源管理器”中转到表对象右键单击一个表,说“修改”,然后单击要转换为标识的主键字段,然后在下面您将看到列属性,在那里您需要更改为(is identity)Yes和Idendity Increment 1。