Alter Table Names
Add Id_new Int Identity(10, 1)
Go

Alter Table Names Drop Column ID
Go

Exec sp_rename 'Names.Id_new', 'ID', 'Column'

请检查.
http://***.com/questions/1049210/adding-an-identity- to-an-existing-column [ ^ ]

Please check.
http://***.com/questions/1049210/adding-an-identity-to-an-existing-column[^]

您忘记了列名-它应该在单词"COLUMN"和"INT"之间

You forgot the column name - it should be between the words "COLUMN" and "INT"

删除旧列并添加新列.

Remove the old column and add new one.

--SQL Script:
ALTER TABLE Users DROP PK_Users
GO
ALTER TABLE Users DROP COLUMN UserID
GO
ALTER TABLE Users ADD UserID int NOT NULL IDENTITY(1,1) 
GO
ALTER TABLE Users ADD CONSTRAINT PK_Users PRIMARY KEY CLUSTERED ([UserID] ASC)
GO